251113121569 has 2 divisors, whose sum is σ = 251113121570. Its totient is φ = 251113121568.

The previous prime is 251113121507. The next prime is 251113121593. The reversal of 251113121569 is 965121311152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 250975950625 + 137170944 = 500975^2 + 11712^2 .

It is a cyclic number.

It is not a de Polignac number, because 251113121569 - 2⁹ = 251113121057 is a prime.

It is a super-2 number, since 2×251113121569² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (251113121599) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125556560784 + 125556560785.

It is an arithmetic number, because the mean of its divisors is an integer number (125556560785).

Almost surely, 2^251113121569 is an apocalyptic number.

It is an amenable number.

251113121569 is a deficient number, since it is larger than the sum of its proper divisors (1).

251113121569 is an equidigital number, since it uses as much as digits as its factorization.

251113121569 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16200, while the sum is 37.

The spelling of 251113121569 in words is "two hundred fifty-one billion, one hundred thirteen million, one hundred twenty-one thousand, five hundred sixty-nine".