191989957 has 4 divisors (see below), whose sum is σ = 192088000. Its totient is φ = 191891916.

The previous prime is 191989949. The next prime is 191989979. The reversal of 191989957 is 759989191.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 191989957 - 2³ = 191989949 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 (191989157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46023 + ... + 50020.

It is an arithmetic number, because the mean of its divisors is an integer number (48022000).

Almost surely, 2^191989957 is an apocalyptic number.

It is an amenable number.

191989957 is a deficient number, since it is larger than the sum of its proper divisors (98043).

191989957 is an equidigital number, since it uses as much as digits as its factorization.

191989957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98042.

The product of its digits is 1837080, while the sum is 58.

The square root of 191989957 is about 13856.0440602648. The cubic root of 191989957 is about 576.8897692584.

The spelling of 191989957 in words is "one hundred ninety-one million, nine hundred eighty-nine thousand, nine hundred fifty-seven".