72878731 has 12 divisors (see below), whose sum is σ = 75308400. Its totient is φ = 70510160.

The previous prime is 72878723. The next prime is 72878749. The reversal of 72878731 is 13787827.

It is not a de Polignac number, because 72878731 - 2³ = 72878723 is a prime.

It is a super-2 number, since 2×72878731² = 10622618864340722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72878431) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 489045 + ... + 489193.

It is an arithmetic number, because the mean of its divisors is an integer number (6275700).

Almost surely, 2^72878731 is an apocalyptic number.

72878731 is a gapful number since it is divisible by the number (71) formed by its first and last digit.

72878731 is a deficient number, since it is larger than the sum of its proper divisors (2429669).

72878731 is an equidigital number, since it uses as much as digits as its factorization.

72878731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 386 (or 303 counting only the distinct ones).

The product of its digits is 131712, while the sum is 43.

The square root of 72878731 is about 8536.9040641207. The cubic root of 72878731 is about 417.7023647555.

The spelling of 72878731 in words is "seventy-two million, eight hundred seventy-eight thousand, seven hundred thirty-one".