72784251 has 20 divisors (see below), whose sum is σ = 111260952. Its totient is φ = 47392128.

The previous prime is 72784237. The next prime is 72784273. The reversal of 72784251 is 15248727.

72784251 = T₂₈₆ + T₂₈₇ + ... + T₇₇₁.

It is not a de Polignac number, because 72784251 - 2⁵ = 72784219 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 not an unprimeable number, because it can be changed into a prime (72784951) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 6966 + ... + 13931.

Almost surely, 2^72784251 is an apocalyptic number.

72784251 is the 6966-th pentagonal number.

72784251 is a deficient number, since it is larger than the sum of its proper divisors (38476701).

72784251 is a wasteful number, since it uses less digits than its factorization.

72784251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20952 (or 20943 counting only the distinct ones).

The product of its digits is 31360, while the sum is 36.

The square root of 72784251 is about 8531.3686475266. The cubic root of 72784251 is about 417.5217835575.

The spelling of 72784251 in words is "seventy-two million, seven hundred eighty-four thousand, two hundred fifty-one".