251294891 has 2 divisors, whose sum is σ = 251294892. Its totient is φ = 251294890.

The previous prime is 251294873. The next prime is 251294899. The reversal of 251294891 is 198492152.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 251294891 - 2²² = 247100587 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (251294899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125647445 + 125647446.

It is an arithmetic number, because the mean of its divisors is an integer number (125647446).

Almost surely, 2^251294891 is an apocalyptic number.

251294891 is a deficient number, since it is larger than the sum of its proper divisors (1).

251294891 is an equidigital number, since it uses as much as digits as its factorization.

251294891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 41.

The square root of 251294891 is about 15852.2834632743. The cubic root of 251294891 is about 631.0462927837.

The spelling of 251294891 in words is "two hundred fifty-one million, two hundred ninety-four thousand, eight hundred ninety-one".