80640891 has 24 divisors (see below), whose sum is σ = 120805776. Its totient is φ = 51797760.

The previous prime is 80640881. The next prime is 80640893. The reversal of 80640891 is 19804608.

It is a happy number.

80640891 is a `hidden beast` number, since 8 + 0 + 640 + 8 + 9 + 1 = 666.

It is not a de Polignac number, because 80640891 - 2¹⁴ = 80624507 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (80640893) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29311 + ... + 31943.

It is an arithmetic number, because the mean of its divisors is an integer number (5033574).

Almost surely, 2^80640891 is an apocalyptic number.

80640891 is a deficient number, since it is larger than the sum of its proper divisors (40164885).

80640891 is a wasteful number, since it uses less digits than its factorization.

80640891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2763 (or 2760 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 80640891 is about 8980.0273384885. The cubic root of 80640891 is about 432.0345104889.

The spelling of 80640891 in words is "eighty million, six hundred forty thousand, eight hundred ninety-one".