189921515940 has 384 divisors, whose sum is σ = 675789811200. Its totient is φ = 43893964800.

The previous prime is 189921515933. The next prime is 189921515983. The reversal of 189921515940 is 49515129981.

189921515940 is a `hidden beast` number, since 1 + 89 + 9 + 2 + 1 + 515 + 9 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 15065640 + ... + 15078240.

It is an arithmetic number, because the mean of its divisors is an integer number (1759869300).

Almost surely, 2^189921515940 is an apocalyptic number.

189921515940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 189921515940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (337894905600).

189921515940 is an abundant number, since it is smaller than the sum of its proper divisors (485868295260).

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

189921515940 is a wasteful number, since it uses less digits than its factorization.

189921515940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12764 (or 12756 counting only the distinct ones).

The product of its (nonzero) digits is 1166400, while the sum is 54.

The spelling of 189921515940 in words is "one hundred eighty-nine billion, nine hundred twenty-one million, five hundred fifteen thousand, nine hundred forty".