21440215335664 has 20 divisors (see below), whose sum is σ = 43983971167104. Its totient is φ = 10089513099008.

The previous prime is 21440215335607. The next prime is 21440215335701. The reversal of 21440215335664 is 46653351204412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39412160272 + ... + 39412160815.

Almost surely, 2^{21440215335664} is an apocalyptic number.

It is an amenable number.

21440215335664 is an abundant number, since it is smaller than the sum of its proper divisors (22543755831440).

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

21440215335664 is a wasteful number, since it uses less digits than its factorization.

21440215335664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78824321112 (or 78824321106 counting only the distinct ones).

The product of its (nonzero) digits is 2073600, while the sum is 46.

The spelling of 21440215335664 in words is "twenty-one trillion, four hundred forty billion, two hundred fifteen million, three hundred thirty-five thousand, six hundred sixty-four".