251098961 has 2 divisors, whose sum is σ = 251098962. Its totient is φ = 251098960.

The previous prime is 251098951. The next prime is 251098979. The reversal of 251098961 is 169890152.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 214798336 + 36300625 = 14656^2 + 6025^2 .

It is a cyclic number.

It is not a de Polignac number, because 251098961 - 2¹⁰ = 251097937 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (251098951) 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, 125549480 + 125549481.

It is an arithmetic number, because the mean of its divisors is an integer number (125549481).

Almost surely, 2^251098961 is an apocalyptic number.

It is an amenable number.

251098961 is a deficient number, since it is larger than the sum of its proper divisors (1).

251098961 is an equidigital number, since it uses as much as digits as its factorization.

251098961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 38880, while the sum is 41.

The square root of 251098961 is about 15846.1023914400. The cubic root of 251098961 is about 630.8822450825.

The spelling of 251098961 in words is "two hundred fifty-one million, ninety-eight thousand, nine hundred sixty-one".