21158164554 has 64 divisors (see below), whose sum is σ = 45742475520. Its totient is φ = 6507438080.

The previous prime is 21158164553. The next prime is 21158164561. The reversal of 21158164554 is 45546185112.

It is not an unprimeable number, because it can be changed into a prime (21158164553) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 482554 + ... + 524570.

It is an arithmetic number, because the mean of its divisors is an integer number (714726180).

Almost surely, 2^21158164554 is an apocalyptic number.

21158164554 is an abundant number, since it is smaller than the sum of its proper divisors (24584310966).

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

21158164554 is a wasteful number, since it uses less digits than its factorization.

21158164554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42175.

The product of its digits is 192000, while the sum is 42.

The spelling of 21158164554 in words is "twenty-one billion, one hundred fifty-eight million, one hundred sixty-four thousand, five hundred fifty-four".