251791849 has 2 divisors, whose sum is σ = 251791850. Its totient is φ = 251791848.

The previous prime is 251791751. The next prime is 251791861. The reversal of 251791849 is 948197152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 218093824 + 33698025 = 14768^2 + 5805^2 .

It is a cyclic number.

It is not a de Polignac number, because 251791849 - 2⁷ = 251791721 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 251791799 and 251791808.

It is not a weakly prime, because it can be changed into another prime (251791349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125895924 + 125895925.

It is an arithmetic number, because the mean of its divisors is an integer number (125895925).

Almost surely, 2^251791849 is an apocalyptic number.

It is an amenable number.

251791849 is a deficient number, since it is larger than the sum of its proper divisors (1).

251791849 is an equidigital number, since it uses as much as digits as its factorization.

251791849 is an evil number, because the sum of its binary digits is even.

The product of its digits is 181440, while the sum is 46.

The square root of 251791849 is about 15867.9503717399. The cubic root of 251791849 is about 631.4620022620.

It can be divided in two parts, 25179 and 1849, that added together give a triangular number (27028 = T₂₃₂).

The spelling of 251791849 in words is "two hundred fifty-one million, seven hundred ninety-one thousand, eight hundred forty-nine".