72505278 has 24 divisors (see below), whose sum is σ = 162513000. Its totient is φ = 23334864.

The previous prime is 72505253. The next prime is 72505283. The reversal of 72505278 is 87250527.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 68928 + ... + 69971.

It is an arithmetic number, because the mean of its divisors is an integer number (6771375).

Almost surely, 2^72505278 is an apocalyptic number.

72505278 is an abundant number, since it is smaller than the sum of its proper divisors (90007722).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

72505278 is a wasteful number, since it uses less digits than its factorization.

72505278 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138936 (or 138933 counting only the distinct ones).

The product of its (nonzero) digits is 39200, while the sum is 36.

The square root of 72505278 is about 8515.0031121545. The cubic root of 72505278 is about 416.9876641797.

The spelling of 72505278 in words is "seventy-two million, five hundred five thousand, two hundred seventy-eight".