80520813 has 6 divisors (see below), whose sum is σ = 116307854. Its totient is φ = 53680536.

The previous prime is 80520809. The next prime is 80520821. The reversal of 80520813 is 31802508.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 80514729 + 6084 = 8973^2 + 78^2 .

It is not a de Polignac number, because 80520813 - 2² = 80520809 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (80520863) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4473370 + ... + 4473387.

Almost surely, 2^80520813 is an apocalyptic number.

It is an amenable number.

80520813 is a deficient number, since it is larger than the sum of its proper divisors (35787041).

80520813 is a wasteful number, since it uses less digits than its factorization.

80520813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8946763 (or 8946760 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 80520813 is about 8973.3390106470. The cubic root of 80520813 is about 431.8199642038.

The spelling of 80520813 in words is "eighty million, five hundred twenty thousand, eight hundred thirteen".