21768926508 has 72 divisors (see below), whose sum is σ = 62904208640. Its totient is φ = 6218091360.

The previous prime is 21768926497. The next prime is 21768926519. The reversal of 21768926508 is 80562986712.

It is an interprime number because it is at equal distance from previous prime (21768926497) and next prime (21768926519).

It is a super-2 number, since 2×21768926508² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1254153 + ... + 1271391.

Almost surely, 2^21768926508 is an apocalyptic number.

21768926508 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21768926508 is an abundant number, since it is smaller than the sum of its proper divisors (41135282132).

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

21768926508 is a wasteful number, since it uses less digits than its factorization.

21768926508 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22267 (or 22262 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 54.

The spelling of 21768926508 in words is "twenty-one billion, seven hundred sixty-eight million, nine hundred twenty-six thousand, five hundred eight".