21204254331416 has 64 divisors (see below), whose sum is σ = 45612780998400. Its totient is φ = 9159790981248.

The previous prime is 21204254331371. The next prime is 21204254331443. The reversal of 21204254331416 is 61413345240212.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a self number, because there is not a number n which added to its sum of digits gives 21204254331416.

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, 64479956 + ... + 64807971.

It is an arithmetic number, because the mean of its divisors is an integer number (712699703100).

Almost surely, 2^{21204254331416} is an apocalyptic number.

21204254331416 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21204254331416 is an abundant number, since it is smaller than the sum of its proper divisors (24408526666984).

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

21204254331416 is a wasteful number, since it uses less digits than its factorization.

21204254331416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129288048 (or 129288044 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 38.

Adding to 21204254331416 its reverse (61413345240212), we get a palindrome (82617599571628).

The spelling of 21204254331416 in words is "twenty-one trillion, two hundred four billion, two hundred fifty-four million, three hundred thirty-one thousand, four hundred sixteen".