189507997 has 4 divisors (see below), whose sum is σ = 216580576. Its totient is φ = 162435420.

The previous prime is 189507979. The next prime is 189508031. The reversal of 189507997 is 799705981.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 799705981 = 101 ⋅7917881.

It is a de Polignac number, because none of the positive numbers 2^k-189507997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189507397) 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, 13536279 + ... + 13536292.

It is an arithmetic number, because the mean of its divisors is an integer number (54145144).

Almost surely, 2^189507997 is an apocalyptic number.

It is an amenable number.

189507997 is a deficient number, since it is larger than the sum of its proper divisors (27072579).

189507997 is an equidigital number, since it uses as much as digits as its factorization.

189507997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27072578.

The product of its (nonzero) digits is 1428840, while the sum is 55.

The square root of 189507997 is about 13766.1903589918. The cubic root of 189507997 is about 574.3930553396.

The spelling of 189507997 in words is "one hundred eighty-nine million, five hundred seven thousand, nine hundred ninety-seven".