21077137508 has 12 divisors (see below), whose sum is σ = 42154275072. Its totient is φ = 9033058920.

The previous prime is 21077137481. The next prime is 21077137547. The reversal of 21077137508 is 80573177012.

21077137508 is an admirable number.

It is a super-2 number, since 2×21077137508² (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 3 ways as a sum of consecutive naturals, for example, 376377428 + ... + 376377483.

It is an arithmetic number, because the mean of its divisors is an integer number (3512856256).

Almost surely, 2^21077137508 is an apocalyptic number.

21077137508 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21077137508 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21077137508 is a wasteful number, since it uses less digits than its factorization.

21077137508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 752754922 (or 752754920 counting only the distinct ones).

The product of its (nonzero) digits is 82320, while the sum is 41.

The spelling of 21077137508 in words is "twenty-one billion, seventy-seven million, one hundred thirty-seven thousand, five hundred eight".