189819780172 has 12 divisors (see below), whose sum is σ = 362383216776. Its totient is φ = 86281718240.

The previous prime is 189819780077. The next prime is 189819780179. The reversal of 189819780172 is 271087918981.

It is a self number, because there is not a number n which added to its sum of digits gives 189819780172.

It is not an unprimeable number, because it can be changed into a prime (189819780179) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2157042913 + ... + 2157043000.

It is an arithmetic number, because the mean of its divisors is an integer number (30198601398).

Almost surely, 2^189819780172 is an apocalyptic number.

It is an amenable number.

189819780172 is a deficient number, since it is larger than the sum of its proper divisors (172563436604).

189819780172 is a wasteful number, since it uses less digits than its factorization.

189819780172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4314085928 (or 4314085926 counting only the distinct ones).

The product of its (nonzero) digits is 4064256, while the sum is 61.

The spelling of 189819780172 in words is "one hundred eighty-nine billion, eight hundred nineteen million, seven hundred eighty thousand, one hundred seventy-two".