21864037188 has 48 divisors (see below), whose sum is σ = 59879894144. Its totient is φ = 6078032640.

The previous prime is 21864037177. The next prime is 21864037249. The reversal of 21864037188 is 88173046812.

It is a super-2 number, since 2×21864037188² (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 (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3514273 + ... + 3520488.

Almost surely, 2^21864037188 is an apocalyptic number.

21864037188 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21864037188 is an abundant number, since it is smaller than the sum of its proper divisors (38015856956).

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

21864037188 is a wasteful number, since it uses less digits than its factorization.

21864037188 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7034812 (or 7034810 counting only the distinct ones).

The product of its (nonzero) digits is 516096, while the sum is 48.

The spelling of 21864037188 in words is "twenty-one billion, eight hundred sixty-four million, thirty-seven thousand, one hundred eighty-eight".