191191851 has 12 divisors (see below), whose sum is σ = 290701320. Its totient is φ = 120752640.

The previous prime is 191191841. The next prime is 191191879. The reversal of 191191851 is 158191191.

It is not a de Polignac number, because 191191851 - 2¹⁵ = 191159083 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (191191831) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 558870 + ... + 559211.

It is an arithmetic number, because the mean of its divisors is an integer number (24225110).

Almost surely, 2^191191851 is an apocalyptic number.

191191851 is a deficient number, since it is larger than the sum of its proper divisors (99509469).

191191851 is a wasteful number, since it uses less digits than its factorization.

191191851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1118106 (or 1118103 counting only the distinct ones).

The product of its digits is 3240, while the sum is 36.

The square root of 191191851 is about 13827.2141445774. The cubic root of 191191851 is about 576.0892783344.

The spelling of 191191851 in words is "one hundred ninety-one million, one hundred ninety-one thousand, eight hundred fifty-one".