72168640 has 28 divisors (see below), whose sum is σ = 171852336. Its totient is φ = 28867328.

The previous prime is 72168601. The next prime is 72168643. The reversal of 72168640 is 4686127.

It is a junction number, because it is equal to n+sod(n) for n = 72168596 and 72168605.

It is not an unprimeable number, because it can be changed into a prime (72168643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 112444 + ... + 113083.

Almost surely, 2^72168640 is an apocalyptic number.

It is an amenable number.

72168640 is an abundant number, since it is smaller than the sum of its proper divisors (99683696).

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

72168640 is a wasteful number, since it uses less digits than its factorization.

72168640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225544 (or 225534 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 72168640 is about 8495.2127695544. The cubic root of 72168640 is about 416.3413125912.

The spelling of 72168640 in words is "seventy-two million, one hundred sixty-eight thousand, six hundred forty".