191372661 has 24 divisors (see below), whose sum is σ = 285661376. Its totient is φ = 123379200.

The previous prime is 191372647. The next prime is 191372663. The reversal of 191372661 is 166273191.

It is not a de Polignac number, because 191372661 - 2¹⁰ = 191371637 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 (191372663) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 37461 + ... + 42261.

Almost surely, 2^191372661 is an apocalyptic number.

It is an amenable number.

191372661 is a deficient number, since it is larger than the sum of its proper divisors (94288715).

191372661 is a wasteful number, since it uses less digits than its factorization.

191372661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4953 (or 4950 counting only the distinct ones).

The product of its digits is 13608, while the sum is 36.

The square root of 191372661 is about 13833.7507928978. The cubic root of 191372661 is about 576.2708235268.

The spelling of 191372661 in words is "one hundred ninety-one million, three hundred seventy-two thousand, six hundred sixty-one".