191791457 has 16 divisors (see below), whose sum is σ = 235122048. Its totient is φ = 153943680.

The previous prime is 191791441. The next prime is 191791469. The reversal of 191791457 is 754197191.

It is not a de Polignac number, because 191791457 - 2⁴ = 191791441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (191791417) 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 15 ways as a sum of consecutive naturals, for example, 25868 + ... + 32445.

It is an arithmetic number, because the mean of its divisors is an integer number (14695128).

Almost surely, 2^191791457 is an apocalyptic number.

It is an amenable number.

191791457 is a deficient number, since it is larger than the sum of its proper divisors (43330591).

191791457 is a wasteful number, since it uses less digits than its factorization.

191791457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58360.

The product of its digits is 79380, while the sum is 44.

The square root of 191791457 is about 13848.8792687351. The cubic root of 191791457 is about 576.6908836693.

The spelling of 191791457 in words is "one hundred ninety-one million, seven hundred ninety-one thousand, four hundred fifty-seven".