120972491721 has 27 divisors (see below), whose sum is σ = 175947555693. Its totient is φ = 80093917080.

The previous prime is 120972491707. The next prime is 120972491747. The reversal of 120972491721 is 127194279021.

It is a happy number.

The square root of 120972491721 is 347811.

It is a perfect power (a square), and thus also a powerful number.

120972491721 is a `hidden beast` number, since 1 + 2 + 0 + 97 + 2 + 491 + 72 + 1 = 666.

It is not a de Polignac number, because 120972491721 - 2⁹ = 120972491209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (120972491701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 199295400 + ... + 199296006.

Almost surely, 2^120972491721 is an apocalyptic number.

120972491721 is the 347811-st square number.

120972491721 is the 173906-th centered octagonal number.

It is an amenable number.

120972491721 is a deficient number, since it is larger than the sum of its proper divisors (54975063972).

120972491721 is an frugal number, since it uses more digits than its factorization.

120972491721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1602 (or 801 counting only the distinct ones).

The product of its (nonzero) digits is 127008, while the sum is 45.

The spelling of 120972491721 in words is "one hundred twenty billion, nine hundred seventy-two million, four hundred ninety-one thousand, seven hundred twenty-one".