80891549 has 4 divisors (see below), whose sum is σ = 81302364. Its totient is φ = 80480736.

The previous prime is 80891533. The next prime is 80891561. The reversal of 80891549 is 94519808.

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 38875225 + 42016324 = 6235^2 + 6482^2 .

It is a cyclic number.

It is not a de Polignac number, because 80891549 - 2⁴ = 80891533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (80891149) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 205112 + ... + 205505.

It is an arithmetic number, because the mean of its divisors is an integer number (20325591).

Almost surely, 2^80891549 is an apocalyptic number.

It is an amenable number.

80891549 is a deficient number, since it is larger than the sum of its proper divisors (410815).

80891549 is a wasteful number, since it uses less digits than its factorization.

80891549 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 410814.

The product of its (nonzero) digits is 103680, while the sum is 44.

The square root of 80891549 is about 8993.9729263546. The cubic root of 80891549 is about 432.4816818731.

The spelling of 80891549 in words is "eighty million, eight hundred ninety-one thousand, five hundred forty-nine".