21621406064334 has 16 divisors (see below), whose sum is σ = 43639535177040. Its totient is φ = 7141014846720.

The previous prime is 21621406064329. The next prime is 21621406064369. The reversal of 21621406064334 is 43346060412612.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16530126307 + ... + 16530127614.

It is an arithmetic number, because the mean of its divisors is an integer number (2727470948565).

Almost surely, 2^{21621406064334} is an apocalyptic number.

21621406064334 is an abundant number, since it is smaller than the sum of its proper divisors (22018129112706).

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

21621406064334 is a wasteful number, since it uses less digits than its factorization.

21621406064334 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33060254035.

The product of its (nonzero) digits is 497664, while the sum is 42.

Adding to 21621406064334 its reverse (43346060412612), we get a palindrome (64967466476946).

The spelling of 21621406064334 in words is "twenty-one trillion, six hundred twenty-one billion, four hundred six million, sixty-four thousand, three hundred thirty-four".