251518461641 has 2 divisors, whose sum is σ = 251518461642. Its totient is φ = 251518461640.

The previous prime is 251518461637. The next prime is 251518461713. The reversal of 251518461641 is 146164815152.

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., 216485478400 + 35032983241 = 465280^2 + 187171^2 .

It is a cyclic number.

It is not a de Polignac number, because 251518461641 - 2² = 251518461637 is a prime.

It is a super-3 number, since 3×251518461641³ (a number of 35 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 251518461592 and 251518461601.

It is not a weakly prime, because it can be changed into another prime (251518461241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125759230820 + 125759230821.

It is an arithmetic number, because the mean of its divisors is an integer number (125759230821).

Almost surely, 2^251518461641 is an apocalyptic number.

It is an amenable number.

251518461641 is a deficient number, since it is larger than the sum of its proper divisors (1).

251518461641 is an equidigital number, since it uses as much as digits as its factorization.

251518461641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 230400, while the sum is 44.

The spelling of 251518461641 in words is "two hundred fifty-one billion, five hundred eighteen million, four hundred sixty-one thousand, six hundred forty-one".