249512091691 has 2 divisors, whose sum is σ = 249512091692. Its totient is φ = 249512091690.

The previous prime is 249512091679. The next prime is 249512091701. The reversal of 249512091691 is 196190215942.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 249512091691 - 2¹⁵ = 249512058923 is a prime.

It is not a weakly prime, because it can be changed into another prime (249512091391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124756045845 + 124756045846.

It is an arithmetic number, because the mean of its divisors is an integer number (124756045846).

Almost surely, 2^249512091691 is an apocalyptic number.

249512091691 is a deficient number, since it is larger than the sum of its proper divisors (1).

249512091691 is an equidigital number, since it uses as much as digits as its factorization.

249512091691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 349920, while the sum is 49.

The spelling of 249512091691 in words is "two hundred forty-nine billion, five hundred twelve million, ninety-one thousand, six hundred ninety-one".