80918281 has 4 divisors (see below), whose sum is σ = 80937364. Its totient is φ = 80899200.

The previous prime is 80918267. The next prime is 80918287. The reversal of 80918281 is 18281908.

80918281 is a nontrivial binomial coefficient, being equal to C(12722, 2).

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 47045881 + 33872400 = 6859^2 + 5820^2 .

It is a 3-Lehmer number, since φ(80918281) divides (80918281-1)³.

It is a cyclic number.

It is not a de Polignac number, because 80918281 - 2⁹ = 80917769 is a prime.

It is a super-2 number, since 2×80918281² = 13095536399989922, which contains 22 as substring.

It is a deceptive number, since it divides R_80918280.

It is a self number, because there is not a number n which added to its sum of digits gives 80918281.

It is not an unprimeable number, because it can be changed into a prime (80918287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1 + ... + 12721.

It is an arithmetic number, because the mean of its divisors is an integer number (20234341).

It is a Poulet number, since it divides 2^80918280-1.

Almost surely, 2^80918281 is an apocalyptic number.

80918281 is the 12721-st triangular number and also the 6361-st hexagonal number.

80918281 is the 4241-st centered nonagonal number.

It is an amenable number.

80918281 is a deficient number, since it is larger than the sum of its proper divisors (19083).

80918281 is a wasteful number, since it uses less digits than its factorization.

80918281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19082.

The product of its (nonzero) digits is 9216, while the sum is 37.

The square root of 80918281 is about 8995.4589099167. The cubic root of 80918281 is about 432.5293169564.

The spelling of 80918281 in words is "eighty million, nine hundred eighteen thousand, two hundred eighty-one".