21890406889737 has 8 divisors (see below), whose sum is σ = 32430232429280. Its totient is φ = 14593604593140.

The previous prime is 21890406889691. The next prime is 21890406889753. The reversal of 21890406889737 is 73798860409812.

21890406889737 is a `hidden beast` number, since 2 + 18 + 90 + 406 + 8 + 8 + 97 + 37 = 666.

It is not a de Polignac number, because 21890406889737 - 2²⁶ = 21890339780873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21890406889777) 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, 405377905339 + ... + 405377905392.

It is an arithmetic number, because the mean of its divisors is an integer number (4053779053660).

Almost surely, 2^{21890406889737} is an apocalyptic number.

21890406889737 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

21890406889737 is a deficient number, since it is larger than the sum of its proper divisors (10539825539543).

21890406889737 is an equidigital number, since it uses as much as digits as its factorization.

21890406889737 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 810755810740 (or 810755810734 counting only the distinct ones).

The product of its (nonzero) digits is 292626432, while the sum is 72.

The spelling of 21890406889737 in words is "twenty-one trillion, eight hundred ninety billion, four hundred six million, eight hundred eighty-nine thousand, seven hundred thirty-seven".