72678921 has 16 divisors (see below), whose sum is σ = 111366528. Its totient is φ = 41299200.

The previous prime is 72678889. The next prime is 72678923. The reversal of 72678921 is 12987627.

It is not a de Polignac number, because 72678921 - 2⁵ = 72678889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72678923) 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 15 ways as a sum of consecutive naturals, for example, 5760 + ... + 13361.

It is an arithmetic number, because the mean of its divisors is an integer number (6960408).

Almost surely, 2^72678921 is an apocalyptic number.

It is an amenable number.

72678921 is a deficient number, since it is larger than the sum of its proper divisors (38687607).

72678921 is a wasteful number, since it uses less digits than its factorization.

72678921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19312.

The product of its digits is 84672, while the sum is 42.

The square root of 72678921 is about 8525.1933115912. The cubic root of 72678921 is about 417.3202802559.

The spelling of 72678921 in words is "seventy-two million, six hundred seventy-eight thousand, nine hundred twenty-one".