21438123818888 has 32 divisors (see below), whose sum is σ = 45952933137600. Its totient is φ = 9184948074432.

The previous prime is 21438123818887. The next prime is 21438123818897. The reversal of 21438123818888 is 88881832183412.

It is not an unprimeable number, because it can be changed into a prime (21438123818887) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58550795 + ... + 58915802.

It is an arithmetic number, because the mean of its divisors is an integer number (1436029160550).

Almost surely, 2^{21438123818888} is an apocalyptic number.

21438123818888 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21438123818888 is an abundant number, since it is smaller than the sum of its proper divisors (24514809318712).

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

21438123818888 is a wasteful number, since it uses less digits than its factorization.

21438123818888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117469869 (or 117469865 counting only the distinct ones).

The product of its digits is 37748736, while the sum is 65.

The spelling of 21438123818888 in words is "twenty-one trillion, four hundred thirty-eight billion, one hundred twenty-three million, eight hundred eighteen thousand, eight hundred eighty-eight".