80621857 has 4 divisors (see below), whose sum is σ = 81726340. Its totient is φ = 79517376.

The previous prime is 80621843. The next prime is 80621869. The reversal of 80621857 is 75812608.

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 54774801 + 25847056 = 7401^2 + 5084^2 .

It is a cyclic number.

It is not a de Polignac number, because 80621857 - 2⁷ = 80621729 is a prime.

It is a super-2 number, since 2×80621857² = 12999767652256898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (80621887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 552132 + ... + 552277.

It is an arithmetic number, because the mean of its divisors is an integer number (20431585).

Almost surely, 2^80621857 is an apocalyptic number.

It is an amenable number.

80621857 is a deficient number, since it is larger than the sum of its proper divisors (1104483).

80621857 is a wasteful number, since it uses less digits than its factorization.

80621857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1104482.

The product of its (nonzero) digits is 26880, while the sum is 37.

The square root of 80621857 is about 8978.9674796159. The cubic root of 80621857 is about 432.0005161888. Note that the first 3 decimals are identical.

Subtracting from 80621857 its reverse (75812608), we obtain a square (4809249 = 2193²).

The spelling of 80621857 in words is "eighty million, six hundred twenty-one thousand, eight hundred fifty-seven".