189658721000 has 128 divisors (see below), whose sum is σ = 507398860800. Its totient is φ = 65000563200.

The previous prime is 189658720969. The next prime is 189658721003. The reversal of 189658721000 is 127856981.

It is not an unprimeable number, because it can be changed into a prime (189658721003) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31195961 + ... + 31202039.

It is an arithmetic number, because the mean of its divisors is an integer number (3964053600).

Almost surely, 2^189658721000 is an apocalyptic number.

189658721000 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 189658721000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (253699430400).

189658721000 is an abundant number, since it is smaller than the sum of its proper divisors (317740139800).

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

189658721000 is a wasteful number, since it uses less digits than its factorization.

189658721000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10564 (or 10550 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 47.

The spelling of 189658721000 in words is "one hundred eighty-nine billion, six hundred fifty-eight million, seven hundred twenty-one thousand".