916136721 has 6 divisors (see below), whose sum is σ = 1323308610. Its totient is φ = 610757808.

The previous prime is 916136701. The next prime is 916136723. The reversal of 916136721 is 127631619.

It can be written as a sum of positive squares in only one way, i.e., 607080321 + 309056400 = 24639^2 + 17580^2 .

It is not a de Polignac number, because 916136721 - 2¹¹ = 916134673 is a prime.

It is not an unprimeable number, because it can be changed into a prime (916136723) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 50896476 + ... + 50896493.

It is an arithmetic number, because the mean of its divisors is an integer number (220551435).

Almost surely, 2^916136721 is an apocalyptic number.

It is an amenable number.

916136721 is a deficient number, since it is larger than the sum of its proper divisors (407171889).

916136721 is a wasteful number, since it uses less digits than its factorization.

916136721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101792975 (or 101792972 counting only the distinct ones).

The product of its digits is 13608, while the sum is 36.

The square root of 916136721 is about 30267.7505110638. The cubic root of 916136721 is about 971.2255459126.

The spelling of 916136721 in words is "nine hundred sixteen million, one hundred thirty-six thousand, seven hundred twenty-one".