21831536690929 has 75 divisors (see below), whose sum is σ = 27444995536377. Its totient is φ = 17315588464776.

The previous prime is 21831536690881. The next prime is 21831536690933. The reversal of 21831536690929 is 92909663513812.

The square root of 21831536690929 is 4672423.

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

It is not a de Polignac number, because 21831536690929 - 2¹⁷ = 21831536559857 is a prime.

It is a taxicab number since it can be written as a sum of two cubes in more than one way. Here 21831536690929 = 7353³ + 27778³ = 13072³ + 26961³.

It is not an unprimeable number, because it can be changed into a prime (21831536690939) by changing a digit.

It is a polite number, since it can be written in 74 ways as a sum of consecutive naturals, for example, 507710155582 + ... + 507710155624.

Almost surely, 2^{21831536690929} is an apocalyptic number.

21831536690929 is the 4672423-rd square number.

21831536690929 is the 2336212-nd centered octagonal number.

It is an amenable number.

21831536690929 is a deficient number, since it is larger than the sum of its proper divisors (5613458845448).

21831536690929 is an frugal number, since it uses more digits than its factorization.

21831536690929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262 (or 69 counting only the distinct ones).

The product of its (nonzero) digits is 37791360, while the sum is 64.

The spelling of 21831536690929 in words is "twenty-one trillion, eight hundred thirty-one billion, five hundred thirty-six million, six hundred ninety thousand, nine hundred twenty-nine".