72920857 has 4 divisors (see below), whose sum is σ = 74009296. Its totient is φ = 71832420.

The previous prime is 72920843. The next prime is 72920863. The reversal of 72920857 is 75802927.

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 not a de Polignac number, because 72920857 - 2²³ = 64532249 is a prime.

It is a super-2 number, since 2×72920857² = 10634902771228898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72920657) 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 3 ways as a sum of consecutive naturals, for example, 544119 + ... + 544252.

It is an arithmetic number, because the mean of its divisors is an integer number (18502324).

Almost surely, 2^72920857 is an apocalyptic number.

It is an amenable number.

72920857 is a deficient number, since it is larger than the sum of its proper divisors (1088439).

72920857 is a wasteful number, since it uses less digits than its factorization.

72920857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1088438.

The product of its (nonzero) digits is 70560, while the sum is 40.

The square root of 72920857 is about 8539.3709955710. The cubic root of 72920857 is about 417.7828305754.

The spelling of 72920857 in words is "seventy-two million, nine hundred twenty thousand, eight hundred fifty-seven".