251134021 has 2 divisors, whose sum is σ = 251134022. Its totient is φ = 251134020.

The previous prime is 251133973. The next prime is 251134043. The reversal of 251134021 is 120431152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 250873921 + 260100 = 15839^2 + 510^2 .

It is a cyclic number.

It is not a de Polignac number, because 251134021 - 2²¹ = 249036869 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 251134021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (251134321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125567010 + 125567011.

It is an arithmetic number, because the mean of its divisors is an integer number (125567011).

Almost surely, 2^251134021 is an apocalyptic number.

It is an amenable number.

251134021 is a deficient number, since it is larger than the sum of its proper divisors (1).

251134021 is an equidigital number, since it uses as much as digits as its factorization.

251134021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 251134021 is about 15847.2086185549. The cubic root of 251134021 is about 630.9116062848.

Adding to 251134021 its reverse (120431152), we get a palindrome (371565173).

The spelling of 251134021 in words is "two hundred fifty-one million, one hundred thirty-four thousand, twenty-one".