21109802855031 has 48 divisors (see below), whose sum is σ = 33676800498432. Its totient is φ = 12635135049600.

The previous prime is 21109802854997. The next prime is 21109802855069. The reversal of 21109802855031 is 13055820890112.

21109802855031 is a `hidden beast` number, since 2 + 1 + 1 + 0 + 98 + 0 + 2 + 8 + 550 + 3 + 1 = 666.

It is not a de Polignac number, because 21109802855031 - 2⁶ = 21109802854967 is a prime.

It is a super-2 number, since 2×21109802855031² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21109802855231) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 22473411 + ... + 23393883.

It is an arithmetic number, because the mean of its divisors is an integer number (701600010384).

Almost surely, 2^{21109802855031} is an apocalyptic number.

21109802855031 is a deficient number, since it is larger than the sum of its proper divisors (12566997643401).

21109802855031 is a wasteful number, since it uses less digits than its factorization.

21109802855031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 923364 (or 923361 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 45.

The spelling of 21109802855031 in words is "twenty-one trillion, one hundred nine billion, eight hundred two million, eight hundred fifty-five thousand, thirty-one".