251506284401 has 2 divisors, whose sum is σ = 251506284402. Its totient is φ = 251506284400.

The previous prime is 251506284377. The next prime is 251506284409. The reversal of 251506284401 is 104482605152.

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., 175108771600 + 76397512801 = 418460^2 + 276401^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-251506284401 is a prime.

It is a super-2 number, since 2×251506284401² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (251506284409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125753142200 + 125753142201.

It is an arithmetic number, because the mean of its divisors is an integer number (125753142201).

Almost surely, 2^251506284401 is an apocalyptic number.

It is an amenable number.

251506284401 is a deficient number, since it is larger than the sum of its proper divisors (1).

251506284401 is an equidigital number, since it uses as much as digits as its factorization.

251506284401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 76800, while the sum is 38.

Adding to 251506284401 its reverse (104482605152), we get a palindrome (355988889553).

The spelling of 251506284401 in words is "two hundred fifty-one billion, five hundred six million, two hundred eighty-four thousand, four hundred one".