191521453 has 2 divisors, whose sum is σ = 191521454. Its totient is φ = 191521452.

The previous prime is 191521433. The next prime is 191521459. The reversal of 191521453 is 354125191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 188183524 + 3337929 = 13718^2 + 1827^2 .

It is a cyclic number.

It is not a de Polignac number, because 191521453 - 2⁹ = 191520941 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191521459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95760726 + 95760727.

It is an arithmetic number, because the mean of its divisors is an integer number (95760727).

Almost surely, 2^191521453 is an apocalyptic number.

It is an amenable number.

191521453 is a deficient number, since it is larger than the sum of its proper divisors (1).

191521453 is an equidigital number, since it uses as much as digits as its factorization.

191521453 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5400, while the sum is 31.

The square root of 191521453 is about 13839.1276097881. The cubic root of 191521453 is about 576.4201347807.

The spelling of 191521453 in words is "one hundred ninety-one million, five hundred twenty-one thousand, four hundred fifty-three".