21880637128 has 32 divisors (see below), whose sum is σ = 47125108800. Its totient is φ = 9329810112.

The previous prime is 21880637113. The next prime is 21880637167. The reversal of 21880637128 is 82173608812.

It is a super-2 number, since 2×21880637128² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 980658 + ... + 1002721.

It is an arithmetic number, because the mean of its divisors is an integer number (1472659650).

Almost surely, 2^21880637128 is an apocalyptic number.

21880637128 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21880637128 is an abundant number, since it is smaller than the sum of its proper divisors (25244471672).

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

21880637128 is a wasteful number, since it uses less digits than its factorization.

21880637128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1983589 (or 1983585 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 46.

The spelling of 21880637128 in words is "twenty-one billion, eight hundred eighty million, six hundred thirty-seven thousand, one hundred twenty-eight".