21344639764 has 24 divisors (see below), whose sum is σ = 42722624448. Its totient is φ = 9140557440.

The previous prime is 21344639713. The next prime is 21344639783. The reversal of 21344639764 is 46793644312.

It is a hoax number, since the sum of its digits (49) coincides with the sum of the digits of its distinct prime factors.

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, 261157 + ... + 333004.

It is an arithmetic number, because the mean of its divisors is an integer number (1780109352).

Almost surely, 2^21344639764 is an apocalyptic number.

It is an amenable number.

21344639764 is an abundant number, since it is smaller than the sum of its proper divisors (21377984684).

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

21344639764 is a wasteful number, since it uses less digits than its factorization.

21344639764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 595455 (or 595453 counting only the distinct ones).

The product of its digits is 2612736, while the sum is 49.

The spelling of 21344639764 in words is "twenty-one billion, three hundred forty-four million, six hundred thirty-nine thousand, seven hundred sixty-four".