21139313664 has 352 divisors, whose sum is σ = 70010675200. Its totient is φ = 5534023680.

The previous prime is 21139313659. The next prime is 21139313681. The reversal of 21139313664 is 46631393112.

It is a happy number.

It is a congruent number.

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, 12665022 + ... + 12666690.

Almost surely, 2^21139313664 is an apocalyptic number.

21139313664 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 21139313664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35005337600).

21139313664 is an abundant number, since it is smaller than the sum of its proper divisors (48871361536).

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

21139313664 is a wasteful number, since it uses less digits than its factorization.

21139313664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1749 (or 1731 counting only the distinct ones).

The product of its digits is 69984, while the sum is 39.

The spelling of 21139313664 in words is "twenty-one billion, one hundred thirty-nine million, three hundred thirteen thousand, six hundred sixty-four".