251266649 has 2 divisors, whose sum is σ = 251266650. Its totient is φ = 251266648.

The previous prime is 251266633. The next prime is 251266661. The reversal of 251266649 is 946662152.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 151905625 + 99361024 = 12325^2 + 9968^2 .

It is a cyclic number.

It is not a de Polignac number, because 251266649 - 2⁴ = 251266633 is a prime.

It is not a weakly prime, because it can be changed into another prime (251266679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125633324 + 125633325.

It is an arithmetic number, because the mean of its divisors is an integer number (125633325).

Almost surely, 2^251266649 is an apocalyptic number.

It is an amenable number.

251266649 is a deficient number, since it is larger than the sum of its proper divisors (1).

251266649 is an equidigital number, since it uses as much as digits as its factorization.

251266649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 155520, while the sum is 41.

The square root of 251266649 is about 15851.3926517515. The cubic root of 251266649 is about 631.0226516649.

The spelling of 251266649 in words is "two hundred fifty-one million, two hundred sixty-six thousand, six hundred forty-nine".