21550205976 has 64 divisors (see below), whose sum is σ = 58594324320. Its totient is φ = 6565171200.

The previous prime is 21550205969. The next prime is 21550205993. The reversal of 21550205976 is 67950205512.

It is a super-2 number, since 2×21550205976² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 310425 + ... + 373448.

Almost surely, 2^21550205976 is an apocalyptic number.

21550205976 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21550205976 is an abundant number, since it is smaller than the sum of its proper divisors (37044118344).

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

21550205976 is a wasteful number, since it uses less digits than its factorization.

21550205976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 683996 (or 683992 counting only the distinct ones).

The product of its (nonzero) digits is 189000, while the sum is 42.

The spelling of 21550205976 in words is "twenty-one billion, five hundred fifty million, two hundred five thousand, nine hundred seventy-six".