72428391 has 16 divisors (see below), whose sum is σ = 122630400. Its totient is φ = 41387544.

The previous prime is 72428387. The next prime is 72428441. The reversal of 72428391 is 19382427.

It is not a de Polignac number, because 72428391 - 2² = 72428387 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72428791) 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, 191421 + ... + 191798.

It is an arithmetic number, because the mean of its divisors is an integer number (7664400).

Almost surely, 2^72428391 is an apocalyptic number.

72428391 is a deficient number, since it is larger than the sum of its proper divisors (50202009).

72428391 is a wasteful number, since it uses less digits than its factorization.

72428391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 383235 (or 383229 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 72428391 is about 8510.4871188434. The cubic root of 72428391 is about 416.8402162011.

The spelling of 72428391 in words is "seventy-two million, four hundred twenty-eight thousand, three hundred ninety-one".