78680281 has 4 divisors (see below), whose sum is σ = 78960564. Its totient is φ = 78400000.

The previous prime is 78680279. The next prime is 78680291. The reversal of 78680281 is 18208687.

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 33454656 + 45225625 = 5784^2 + 6725^2 .

It is a 5-Lehmer number, since φ(78680281) divides (78680281-1)⁵.

It is a cyclic number.

It is not a de Polignac number, because 78680281 - 2¹ = 78680279 is a prime.

It is a super-2 number, since 2×78680281² = 12381173236477922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78680291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 139720 + ... + 140281.

It is an arithmetic number, because the mean of its divisors is an integer number (19740141).

Almost surely, 2^78680281 is an apocalyptic number.

It is an amenable number.

78680281 is a deficient number, since it is larger than the sum of its proper divisors (280283).

78680281 is a wasteful number, since it uses less digits than its factorization.

78680281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280282.

The product of its (nonzero) digits is 43008, while the sum is 40.

The square root of 78680281 is about 8870.1905841983. The cubic root of 78680281 is about 428.5044148288.

It can be divided in two parts, 78680 and 281, that added together give a square (78961 = 281²).

The spelling of 78680281 in words is "seventy-eight million, six hundred eighty thousand, two hundred eighty-one".