72661578 has 16 divisors (see below), whose sum is σ = 158534496. Its totient is φ = 22018640.

The previous prime is 72661573. The next prime is 72661579. The reversal of 72661578 is 87516627.

It is not an unprimeable number, because it can be changed into a prime (72661571) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 550401 + ... + 550532.

It is an arithmetic number, because the mean of its divisors is an integer number (9908406).

Almost surely, 2^72661578 is an apocalyptic number.

72661578 is an abundant number, since it is smaller than the sum of its proper divisors (85872918).

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

72661578 is a wasteful number, since it uses less digits than its factorization.

72661578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1100949.

The product of its digits is 141120, while the sum is 42.

The square root of 72661578 is about 8524.1760892182. The cubic root of 72661578 is about 417.2870832790.

The spelling of 72661578 in words is "seventy-two million, six hundred sixty-one thousand, five hundred seventy-eight".