21121525776 has 80 divisors (see below), whose sum is σ = 60349373504. Its totient is φ = 6323277312.

The previous prime is 21121525729. The next prime is 21121525783. The reversal of 21121525776 is 67752512112.

It is a super-2 number, since 2×21121525776² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 434326 + ... + 480501.

Almost surely, 2^21121525776 is an apocalyptic number.

21121525776 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21121525776 is an abundant number, since it is smaller than the sum of its proper divisors (39227847728).

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

21121525776 is a wasteful number, since it uses less digits than its factorization.

21121525776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 914888 (or 914882 counting only the distinct ones).

The product of its digits is 58800, while the sum is 39.

The spelling of 21121525776 in words is "twenty-one billion, one hundred twenty-one million, five hundred twenty-five thousand, seven hundred seventy-six".