251222639 has 2 divisors, whose sum is σ = 251222640. Its totient is φ = 251222638.

The previous prime is 251222633. The next prime is 251222663. The reversal of 251222639 is 936222152.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 251222639 - 2¹² = 251218543 is a prime.

It is a super-2 number, since 2×251222639² = 126225628692248642, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (251222633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125611319 + 125611320.

It is an arithmetic number, because the mean of its divisors is an integer number (125611320).

Almost surely, 2^251222639 is an apocalyptic number.

251222639 is a deficient number, since it is larger than the sum of its proper divisors (1).

251222639 is an equidigital number, since it uses as much as digits as its factorization.

251222639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12960, while the sum is 32.

The square root of 251222639 is about 15850.0043848574. The cubic root of 251222639 is about 630.9858077668.

The spelling of 251222639 in words is "two hundred fifty-one million, two hundred twenty-two thousand, six hundred thirty-nine".