72309915 has 40 divisors (see below), whose sum is σ = 136458960. Its totient is φ = 36531648.

The previous prime is 72309901. The next prime is 72309917. The reversal of 72309915 is 51990327.

It is not a de Polignac number, because 72309915 - 2¹⁰ = 72308891 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 72309915.

It is not an unprimeable number, because it can be changed into a prime (72309917) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 2997 + ... + 12393.

It is an arithmetic number, because the mean of its divisors is an integer number (3411474).

Almost surely, 2^72309915 is an apocalyptic number.

72309915 is a deficient number, since it is larger than the sum of its proper divisors (64149045).

72309915 is a wasteful number, since it uses less digits than its factorization.

72309915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9433 (or 9424 counting only the distinct ones).

The product of its (nonzero) digits is 17010, while the sum is 36.

The square root of 72309915 is about 8503.5236813923. The cubic root of 72309915 is about 416.6128076162.

The spelling of 72309915 in words is "seventy-two million, three hundred nine thousand, nine hundred fifteen".