191977851 has 8 divisors (see below), whose sum is σ = 275660560. Its totient is φ = 118140192.

The previous prime is 191977817. The next prime is 191977853. The reversal of 191977851 is 158779191.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 191977851 - 2⁹ = 191977339 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 191977851.

It is not an unprimeable number, because it can be changed into a prime (191977853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2461216 + ... + 2461293.

It is an arithmetic number, because the mean of its divisors is an integer number (34457570).

Almost surely, 2^191977851 is an apocalyptic number.

191977851 is a deficient number, since it is larger than the sum of its proper divisors (83682709).

191977851 is a wasteful number, since it uses less digits than its factorization.

191977851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4922525.

The product of its digits is 158760, while the sum is 48.

The square root of 191977851 is about 13855.6072043054. The cubic root of 191977851 is about 576.8776436687.

The spelling of 191977851 in words is "one hundred ninety-one million, nine hundred seventy-seven thousand, eight hundred fifty-one".