188439936990 has 64 divisors (see below), whose sum is σ = 464769956160. Its totient is φ = 48861895680.

The previous prime is 188439936973. The next prime is 188439937087. The reversal of 188439936990 is 99639934881.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1746946 + ... + 1851674.

It is an arithmetic number, because the mean of its divisors is an integer number (7262030565).

Almost surely, 2^188439936990 is an apocalyptic number.

188439936990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 188439936990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (232384978080).

188439936990 is an abundant number, since it is smaller than the sum of its proper divisors (276330019170).

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

188439936990 is a wasteful number, since it uses less digits than its factorization.

188439936990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106397.

The product of its (nonzero) digits is 90699264, while the sum is 69.

The spelling of 188439936990 in words is "one hundred eighty-eight billion, four hundred thirty-nine million, nine hundred thirty-six thousand, nine hundred ninety".