191930121 has 8 divisors (see below), whose sum is σ = 284340960. Its totient is φ = 127953396.

The previous prime is 191930069. The next prime is 191930131. The reversal of 191930121 is 121039191.

191930121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 191930121 - 2¹⁸ = 191667977 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 7108523 = 191930121 / (1 + 9 + 1 + 9 + 3 + 0 + 1 + 2 + 1).

It is not an unprimeable number, because it can be changed into a prime (191930131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3554235 + ... + 3554288.

It is an arithmetic number, because the mean of its divisors is an integer number (35542620).

Almost surely, 2^191930121 is an apocalyptic number.

It is an amenable number.

191930121 is a deficient number, since it is larger than the sum of its proper divisors (92410839).

191930121 is an equidigital number, since it uses as much as digits as its factorization.

191930121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7108532 (or 7108526 counting only the distinct ones).

The product of its (nonzero) digits is 486, while the sum is 27.

The square root of 191930121 is about 13853.8846898623. The cubic root of 191930121 is about 576.8298314654.

The spelling of 191930121 in words is "one hundred ninety-one million, nine hundred thirty thousand, one hundred twenty-one".