21216106512264 has 128 divisors (see below), whose sum is σ = 56268894528000. Its totient is φ = 6647398617600.

The previous prime is 21216106512247. The next prime is 21216106512277. The reversal of 21216106512264 is 46221560161212.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 338014644 + ... + 338077404.

It is an arithmetic number, because the mean of its divisors is an integer number (439600738500).

Almost surely, 2^{21216106512264} is an apocalyptic number.

21216106512264 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21216106512264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28134447264000).

21216106512264 is an abundant number, since it is smaller than the sum of its proper divisors (35052788015736).

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

21216106512264 is a wasteful number, since it uses less digits than its factorization.

21216106512264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68579 (or 68575 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 39.

Adding to 21216106512264 its reverse (46221560161212), we get a palindrome (67437666673476).

The spelling of 21216106512264 in words is "twenty-one trillion, two hundred sixteen billion, one hundred six million, five hundred twelve thousand, two hundred sixty-four".