80900721 has 24 divisors (see below), whose sum is σ = 131744480. Its totient is φ = 49028760.

The previous prime is 80900713. The next prime is 80900723. The reversal of 80900721 is 12700908.

It is not a de Polignac number, because 80900721 - 2³ = 80900713 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (80900723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9115 + ... + 15648.

Almost surely, 2^80900721 is an apocalyptic number.

It is an amenable number.

80900721 is a deficient number, since it is larger than the sum of its proper divisors (50843759).

80900721 is a wasteful number, since it uses less digits than its factorization.

80900721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24794 (or 24777 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 80900721 is about 8994.4828089224. The cubic root of 80900721 is about 432.4980270996.

The spelling of 80900721 in words is "eighty million, nine hundred thousand, seven hundred twenty-one".