21158117558 has 32 divisors (see below), whose sum is σ = 33003832320. Its totient is φ = 10165506880.

The previous prime is 21158117543. The next prime is 21158117581. The reversal of 21158117558 is 85571185112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5449778 + ... + 5453658.

It is an arithmetic number, because the mean of its divisors is an integer number (1031369760).

Almost surely, 2^21158117558 is an apocalyptic number.

21158117558 is a deficient number, since it is larger than the sum of its proper divisors (11845714762).

21158117558 is a wasteful number, since it uses less digits than its factorization.

21158117558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4972.

The product of its digits is 112000, while the sum is 44.

The spelling of 21158117558 in words is "twenty-one billion, one hundred fifty-eight million, one hundred seventeen thousand, five hundred fifty-eight".