10645935621721 has 9 divisors (see below), whose sum is σ = 10675339297311. Its totient is φ = 10616612739264.

The previous prime is 10645935621719. The next prime is 10645935621733. The reversal of 10645935621721 is 12712653954601.

The square root of 10645935621721 is 3262811.

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

10645935621721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 2522979615321 + 8122956006400 = 1588389^2 + 2850080^2 .

It is not a de Polignac number, because 10645935621721 - 2¹ = 10645935621719 is a prime.

It is a super-2 number, since 2×10645935621721² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (10645935621701) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1236601065 + ... + 1236609673.

Almost surely, 2^{10645935621721} is an apocalyptic number.

10645935621721 is the 3262811-st square number.

10645935621721 is the 1631406-th centered octagonal number.

It is an amenable number.

10645935621721 is a deficient number, since it is larger than the sum of its proper divisors (29403675590).

10645935621721 is an frugal number, since it uses more digits than its factorization.

10645935621721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17976 (or 8988 counting only the distinct ones).

The product of its (nonzero) digits is 2721600, while the sum is 52.

The spelling of 10645935621721 in words is "ten trillion, six hundred forty-five billion, nine hundred thirty-five million, six hundred twenty-one thousand, seven hundred twenty-one".