80919521 has 4 divisors (see below), whose sum is σ = 80953344. Its totient is φ = 80885700.

The previous prime is 80919493. The next prime is 80919533. The reversal of 80919521 is 12591908.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-80919521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (80919121) 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, 13025 + ... + 18206.

It is an arithmetic number, because the mean of its divisors is an integer number (20238336).

Almost surely, 2^80919521 is an apocalyptic number.

It is an amenable number.

80919521 is a deficient number, since it is larger than the sum of its proper divisors (33823).

80919521 is a wasteful number, since it uses less digits than its factorization.

80919521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33822.

The product of its (nonzero) digits is 6480, while the sum is 35.

The square root of 80919521 is about 8995.5278333181. The cubic root of 80919521 is about 432.5315263196.

The spelling of 80919521 in words is "eighty million, nine hundred nineteen thousand, five hundred twenty-one".