189991968 has 48 divisors (see below), whose sum is σ = 500574816. Its totient is φ = 63096320.

The previous prime is 189991957. The next prime is 189991969. The reversal of 189991968 is 869199981.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is not an unprimeable number, because it can be changed into a prime (189991969) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23455 + ... + 30497.

It is an arithmetic number, because the mean of its divisors is an integer number (10428642).

Almost surely, 2^189991968 is an apocalyptic number.

It is an amenable number.

189991968 is an abundant number, since it is smaller than the sum of its proper divisors (310582848).

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

189991968 is a wasteful number, since it uses less digits than its factorization.

189991968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7337 (or 7329 counting only the distinct ones).

The product of its digits is 2519424, while the sum is 60.

The square root of 189991968 is about 13783.7573977490. The cubic root of 189991968 is about 574.8816068783.

The spelling of 189991968 in words is "one hundred eighty-nine million, nine hundred ninety-one thousand, nine hundred sixty-eight".