251614402021 has 2 divisors, whose sum is σ = 251614402022. Its totient is φ = 251614402020.

The previous prime is 251614402019. The next prime is 251614402031. The reversal of 251614402021 is 120204416152.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 228757497796 + 22856904225 = 478286^2 + 151185^2 .

It is a cyclic number.

It is not a de Polignac number, because 251614402021 - 2¹ = 251614402019 is a prime.

Together with 251614402019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (251614402031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125807201010 + 125807201011.

It is an arithmetic number, because the mean of its divisors is an integer number (125807201011).

Almost surely, 2^251614402021 is an apocalyptic number.

It is an amenable number.

251614402021 is a deficient number, since it is larger than the sum of its proper divisors (1).

251614402021 is an equidigital number, since it uses as much as digits as its factorization.

251614402021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3840, while the sum is 28.

Adding to 251614402021 its reverse (120204416152), we get a palindrome (371818818173).

The spelling of 251614402021 in words is "two hundred fifty-one billion, six hundred fourteen million, four hundred two thousand, twenty-one".