120721700021 has 16 divisors (see below), whose sum is σ = 131270623680. Its totient is φ = 110357164800.

The previous prime is 120721700017. The next prime is 120721700039. The reversal of 120721700021 is 120007127021.

It is a cyclic number.

It is not a de Polignac number, because 120721700021 - 2² = 120721700017 is a prime.

It is a super-2 number, since 2×120721700021² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 120721700021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (120721700521) 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, 641306 + ... + 807908.

It is an arithmetic number, because the mean of its divisors is an integer number (8204413980).

Almost surely, 2^120721700021 is an apocalyptic number.

It is an amenable number.

120721700021 is a deficient number, since it is larger than the sum of its proper divisors (10548923659).

120721700021 is a wasteful number, since it uses less digits than its factorization.

120721700021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167156.

The product of its (nonzero) digits is 392, while the sum is 23.

Adding to 120721700021 its reverse (120007127021), we get a palindrome (240728827042).

The spelling of 120721700021 in words is "one hundred twenty billion, seven hundred twenty-one million, seven hundred thousand, twenty-one".