190115921 has 2 divisors, whose sum is σ = 190115922. Its totient is φ = 190115920.

The previous prime is 190115897. The next prime is 190115923. The reversal of 190115921 is 129511091.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 162919696 + 27196225 = 12764^2 + 5215^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-190115921 is a prime.

It is a super-2 number, since 2×190115921² = 72288126835356482, which contains 22 as substring.

Together with 190115923, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (190115923) 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 as a sum of consecutive naturals, namely, 95057960 + 95057961.

It is an arithmetic number, because the mean of its divisors is an integer number (95057961).

Almost surely, 2^190115921 is an apocalyptic number.

It is an amenable number.

190115921 is a deficient number, since it is larger than the sum of its proper divisors (1).

190115921 is an equidigital number, since it uses as much as digits as its factorization.

190115921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 810, while the sum is 29.

The square root of 190115921 is about 13788.2530075423. The cubic root of 190115921 is about 575.0065995462.

The spelling of 190115921 in words is "one hundred ninety million, one hundred fifteen thousand, nine hundred twenty-one".