191552681 has 2 divisors, whose sum is σ = 191552682. Its totient is φ = 191552680.

The previous prime is 191552677. The next prime is 191552687. The reversal of 191552681 is 186255191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 180768025 + 10784656 = 13445^2 + 3284^2 .

It is a cyclic number.

It is not a de Polignac number, because 191552681 - 2² = 191552677 is a prime.

It is a super-2 number, since 2×191552681² = 73384859196575522, which contains 22 as substring.

It is equal to p_10636679 and since 191552681 and 10636679 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (191552687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95776340 + 95776341.

It is an arithmetic number, because the mean of its divisors is an integer number (95776341).

Almost surely, 2^191552681 is an apocalyptic number.

It is an amenable number.

191552681 is a deficient number, since it is larger than the sum of its proper divisors (1).

191552681 is an equidigital number, since it uses as much as digits as its factorization.

191552681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21600, while the sum is 38.

The square root of 191552681 is about 13840.2558141098. The cubic root of 191552681 is about 576.4514619409.

The spelling of 191552681 in words is "one hundred ninety-one million, five hundred fifty-two thousand, six hundred eighty-one".