21155833153 has 24 divisors (see below), whose sum is σ = 26523205800. Its totient is φ = 16725864960.

The previous prime is 21155833103. The next prime is 21155833177. The reversal of 21155833153 is 35133855112.

It can be written as a sum of positive squares in 4 ways, for example, as 605750544 + 20550082609 = 24612^2 + 143353^2 .

It is not a de Polignac number, because 21155833153 - 2¹⁷ = 21155702081 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21155833103) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 867673 + ... + 891721.

It is an arithmetic number, because the mean of its divisors is an integer number (1105133575).

Almost surely, 2^21155833153 is an apocalyptic number.

It is an amenable number.

21155833153 is a deficient number, since it is larger than the sum of its proper divisors (5367372647).

21155833153 is a wasteful number, since it uses less digits than its factorization.

21155833153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25457 (or 25450 counting only the distinct ones).

The product of its digits is 54000, while the sum is 37.

The spelling of 21155833153 in words is "twenty-one billion, one hundred fifty-five million, eight hundred thirty-three thousand, one hundred fifty-three".