21002122158 has 32 divisors (see below), whose sum is σ = 43842408192. Its totient is φ = 6694512000.

The previous prime is 21002122109. The next prime is 21002122159. The reversal of 21002122158 is 85122120012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002122159) 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, 545958 + ... + 583158.

It is an arithmetic number, because the mean of its divisors is an integer number (1370075256).

Almost surely, 2^21002122158 is an apocalyptic number.

21002122158 is an abundant number, since it is smaller than the sum of its proper divisors (22840286034).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21002122158 is a wasteful number, since it uses less digits than its factorization.

21002122158 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41320.

The product of its (nonzero) digits is 640, while the sum is 24.

The spelling of 21002122158 in words is "twenty-one billion, two million, one hundred twenty-two thousand, one hundred fifty-eight".