80491765 has 4 divisors (see below), whose sum is σ = 96590124. Its totient is φ = 64393408.

The previous prime is 80491759. The next prime is 80491769. The reversal of 80491765 is 56719408.

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 63632529 + 16859236 = 7977^2 + 4106^2 .

It is a cyclic number.

It is not a de Polignac number, because 80491765 - 2⁷ = 80491637 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (80491769) 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, 8049172 + ... + 8049181.

It is an arithmetic number, because the mean of its divisors is an integer number (24147531).

Almost surely, 2^80491765 is an apocalyptic number.

It is an amenable number.

80491765 is a deficient number, since it is larger than the sum of its proper divisors (16098359).

80491765 is a wasteful number, since it uses less digits than its factorization.

80491765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16098358.

The product of its (nonzero) digits is 60480, while the sum is 40.

The square root of 80491765 is about 8971.7202921179. The cubic root of 80491765 is about 431.7680313991.

The spelling of 80491765 in words is "eighty million, four hundred ninety-one thousand, seven hundred sixty-five".