21709919736 has 48 divisors (see below), whose sum is σ = 58846890960. Its totient is φ = 7230585600.

The previous prime is 21709919713. The next prime is 21709919741. The reversal of 21709919736 is 63791990712.

It is a happy number.

It is a super-2 number, since 2×21709919736² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39060 + ... + 212003.

It is an arithmetic number, because the mean of its divisors is an integer number (1225976895).

Almost surely, 2^21709919736 is an apocalyptic number.

It is an amenable number.

21709919736 is an abundant number, since it is smaller than the sum of its proper divisors (37136971224).

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

21709919736 is a wasteful number, since it uses less digits than its factorization.

21709919736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252276 (or 252269 counting only the distinct ones).

The product of its (nonzero) digits is 1285956, while the sum is 54.

The spelling of 21709919736 in words is "twenty-one billion, seven hundred nine million, nine hundred nineteen thousand, seven hundred thirty-six".