191856649 has 2 divisors, whose sum is σ = 191856650. Its totient is φ = 191856648.

The previous prime is 191856641. The next prime is 191856667. The reversal of 191856649 is 946658191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 148718025 + 43138624 = 12195^2 + 6568^2 .

It is a cyclic number.

It is not a de Polignac number, because 191856649 - 2³ = 191856641 is a prime.

It is not a weakly prime, because it can be changed into another prime (191856641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95928324 + 95928325.

It is an arithmetic number, because the mean of its divisors is an integer number (95928325).

Almost surely, 2^191856649 is an apocalyptic number.

It is an amenable number.

191856649 is a deficient number, since it is larger than the sum of its proper divisors (1).

191856649 is an equidigital number, since it uses as much as digits as its factorization.

191856649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 466560, while the sum is 49.

The square root of 191856649 is about 13851.2327610217. The cubic root of 191856649 is about 576.7562174330.

The spelling of 191856649 in words is "one hundred ninety-one million, eight hundred fifty-six thousand, six hundred forty-nine".