21530463664 has 20 divisors (see below), whose sum is σ = 41720593104. Its totient is φ = 10763859008.

The previous prime is 21530463641. The next prime is 21530463673. The reversal of 21530463664 is 46636403512.

It is a happy 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, 50109 + ... + 213475.

Almost surely, 2^21530463664 is an apocalyptic number.

It is an amenable number.

21530463664 is a deficient number, since it is larger than the sum of its proper divisors (20190129440).

21530463664 is a wasteful number, since it uses less digits than its factorization.

21530463664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171612 (or 171606 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 40.

The spelling of 21530463664 in words is "twenty-one billion, five hundred thirty million, four hundred sixty-three thousand, six hundred sixty-four".