251533213 has 2 divisors, whose sum is σ = 251533214. Its totient is φ = 251533212.

The previous prime is 251533201. The next prime is 251533223. The reversal of 251533213 is 312335152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 237560569 + 13972644 = 15413^2 + 3738^2 .

It is a cyclic number.

It is not a de Polignac number, because 251533213 - 2²⁵ = 217978781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (251533223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125766606 + 125766607.

It is an arithmetic number, because the mean of its divisors is an integer number (125766607).

Almost surely, 2^251533213 is an apocalyptic number.

It is an amenable number.

251533213 is a deficient number, since it is larger than the sum of its proper divisors (1).

251533213 is an equidigital number, since it uses as much as digits as its factorization.

251533213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2700, while the sum is 25.

The square root of 251533213 is about 15859.7986431102. The cubic root of 251533213 is about 631.2457194364.

Adding to 251533213 its reverse (312335152), we get a palindrome (563868365).

The spelling of 251533213 in words is "two hundred fifty-one million, five hundred thirty-three thousand, two hundred thirteen".