72780717 has 16 divisors (see below), whose sum is σ = 102199680. Its totient is φ = 45980352.

The previous prime is 72780707. The next prime is 72780731. The reversal of 72780717 is 71708727.

It is a de Polignac number, because none of the positive numbers 2^k-72780717 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72780707) 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, 2683 + ... + 12359.

It is an arithmetic number, because the mean of its divisors is an integer number (6387480).

Almost surely, 2^72780717 is an apocalyptic number.

It is an amenable number.

72780717 is a deficient number, since it is larger than the sum of its proper divisors (29418963).

72780717 is a wasteful number, since it uses less digits than its factorization.

72780717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9812.

The product of its (nonzero) digits is 38416, while the sum is 39.

The square root of 72780717 is about 8531.1615270138. The cubic root of 72780717 is about 417.5150259332.

The spelling of 72780717 in words is "seventy-two million, seven hundred eighty thousand, seven hundred seventeen".