191940457 has 4 divisors (see below), whose sum is σ = 192360916. Its totient is φ = 191520000.

The previous prime is 191940439. The next prime is 191940481. The reversal of 191940457 is 754049191.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 153859216 + 38081241 = 12404^2 + 6171^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191940457 is a prime.

It is a super-2 number, since 2×191940457² = 73682278066737698, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (191940407) 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, 209544 + ... + 210457.

It is an arithmetic number, because the mean of its divisors is an integer number (48090229).

Almost surely, 2^191940457 is an apocalyptic number.

It is an amenable number.

191940457 is a deficient number, since it is larger than the sum of its proper divisors (420459).

191940457 is an equidigital number, since it uses as much as digits as its factorization.

191940457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 420458.

The product of its (nonzero) digits is 45360, while the sum is 40.

The square root of 191940457 is about 13854.2577210040. The cubic root of 191940457 is about 576.8401859390.

The spelling of 191940457 in words is "one hundred ninety-one million, nine hundred forty thousand, four hundred fifty-seven".