191152421 has 2 divisors, whose sum is σ = 191152422. Its totient is φ = 191152420.

The previous prime is 191152343. The next prime is 191152433. The reversal of 191152421 is 124251191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 130530625 + 60621796 = 11425^2 + 7786^2 .

It is a cyclic number.

It is not a de Polignac number, because 191152421 - 2¹⁴ = 191136037 is a prime.

It is a super-2 number, since 2×191152421² = 73078496108322482, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191152121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95576210 + 95576211.

It is an arithmetic number, because the mean of its divisors is an integer number (95576211).

Almost surely, 2^191152421 is an apocalyptic number.

It is an amenable number.

191152421 is a deficient number, since it is larger than the sum of its proper divisors (1).

191152421 is an equidigital number, since it uses as much as digits as its factorization.

191152421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 720, while the sum is 26.

The square root of 191152421 is about 13825.7882596256. The cubic root of 191152421 is about 576.0496728076.

The spelling of 191152421 in words is "one hundred ninety-one million, one hundred fifty-two thousand, four hundred twenty-one".