21451299558 has 16 divisors (see below), whose sum is σ = 46202799216. Its totient is φ = 6600399840.

The previous prime is 21451299557. The next prime is 21451299613. The reversal of 21451299558 is 85599215412.

It is a self number, because there is not a number n which added to its sum of digits gives 21451299558.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21451299557) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 137508253 + ... + 137508408.

It is an arithmetic number, because the mean of its divisors is an integer number (2887674951).

Almost surely, 2^21451299558 is an apocalyptic number.

21451299558 is an abundant number, since it is smaller than the sum of its proper divisors (24751499658).

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

21451299558 is a wasteful number, since it uses less digits than its factorization.

21451299558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275016679.

The product of its digits is 1296000, while the sum is 51.

The spelling of 21451299558 in words is "twenty-one billion, four hundred fifty-one million, two hundred ninety-nine thousand, five hundred fifty-eight".