961188721 has 16 divisors (see below), whose sum is σ = 1032683904. Its totient is φ = 891414784.

The previous prime is 961188691. The next prime is 961188769. The reversal of 961188721 is 127881169.

It is a happy number.

961188721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 961188721 - 2⁵ = 961188689 is a prime.

It is not an unprimeable number, because it can be changed into a prime (961188121) 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, 785316 + ... + 786538.

It is an arithmetic number, because the mean of its divisors is an integer number (64542744).

Almost surely, 2^961188721 is an apocalyptic number.

It is an amenable number.

961188721 is a deficient number, since it is larger than the sum of its proper divisors (71495183).

961188721 is a wasteful number, since it uses less digits than its factorization.

961188721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1880.

The product of its digits is 48384, while the sum is 43.

The square root of 961188721 is about 31003.0437376720. The cubic root of 961188721 is about 986.8918337433.

The spelling of 961188721 in words is "nine hundred sixty-one million, one hundred eighty-eight thousand, seven hundred twenty-one".