72400251 has 32 divisors (see below), whose sum is σ = 125595648. Its totient is φ = 35972640.

The previous prime is 72400247. The next prime is 72400259. The reversal of 72400251 is 15200427.

It is not a de Polignac number, because 72400251 - 2² = 72400247 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (72400259) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1501 + ... + 12126.

It is an arithmetic number, because the mean of its divisors is an integer number (3924864).

Almost surely, 2^72400251 is an apocalyptic number.

72400251 is a deficient number, since it is larger than the sum of its proper divisors (53195397).

72400251 is a wasteful number, since it uses less digits than its factorization.

72400251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13671.

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 72400251 is about 8508.8337038633. The cubic root of 72400251 is about 416.7862253882.

Adding to 72400251 its reverse (15200427), we get a palindrome (87600678).

The spelling of 72400251 in words is "seventy-two million, four hundred thousand, two hundred fifty-one".