72780617 has 16 divisors (see below), whose sum is σ = 91765632. Its totient is φ = 56177280.

The previous prime is 72780599. The next prime is 72780629. The reversal of 72780617 is 71608727.

It is a cyclic number.

It is not a de Polignac number, because 72780617 - 2²⁴ = 56003401 is a prime.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (72780677) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6023 + ... + 13484.

It is an arithmetic number, because the mean of its divisors is an integer number (5735352).

Almost surely, 2^72780617 is an apocalyptic number.

It is an amenable number.

72780617 is a deficient number, since it is larger than the sum of its proper divisors (18985015).

72780617 is a wasteful number, since it uses less digits than its factorization.

72780617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19568.

The product of its (nonzero) digits is 32928, while the sum is 38.

The square root of 72780617 is about 8531.1556661451. The cubic root of 72780617 is about 417.5148347126.

The spelling of 72780617 in words is "seventy-two million, seven hundred eighty thousand, six hundred seventeen".