72665388 has 18 divisors (see below), whose sum is σ = 183682044. Its totient is φ = 24221784.

The previous prime is 72665381. The next prime is 72665389. The reversal of 72665388 is 88356627.

72665388 is a `hidden beast` number, since 7 + 266 + 5 + 388 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×72665388² = 10560517226381088, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (72665381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1009206 + ... + 1009277.

It is an arithmetic number, because the mean of its divisors is an integer number (10204558).

Almost surely, 2^72665388 is an apocalyptic number.

It is an amenable number.

72665388 is an abundant number, since it is smaller than the sum of its proper divisors (111016656).

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

72665388 is a wasteful number, since it uses less digits than its factorization.

72665388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2018493 (or 2018488 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 72665388 is about 8524.3995682981. The cubic root of 72665388 is about 417.2943766154.

The spelling of 72665388 in words is "seventy-two million, six hundred sixty-five thousand, three hundred eighty-eight".