251038627661 has 2 divisors, whose sum is σ = 251038627662. Its totient is φ = 251038627660.

The previous prime is 251038627627. The next prime is 251038627739. The reversal of 251038627661 is 166726830152.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 229147945636 + 21890682025 = 478694^2 + 147955^2 .

It is a cyclic number.

It is not a de Polignac number, because 251038627661 - 2²⁶ = 250971518797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (251038627361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125519313830 + 125519313831.

It is an arithmetic number, because the mean of its divisors is an integer number (125519313831).

Almost surely, 2^251038627661 is an apocalyptic number.

It is an amenable number.

251038627661 is a deficient number, since it is larger than the sum of its proper divisors (1).

251038627661 is an equidigital number, since it uses as much as digits as its factorization.

251038627661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 725760, while the sum is 47.

The spelling of 251038627661 in words is "two hundred fifty-one billion, thirty-eight million, six hundred twenty-seven thousand, six hundred sixty-one".