521531251 has 2 divisors, whose sum is σ = 521531252. Its totient is φ = 521531250.

The previous prime is 521531249. The next prime is 521531327. The reversal of 521531251 is 152135125.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 521531251 - 2¹ = 521531249 is a prime.

Together with 521531249, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (521535251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260765625 + 260765626.

It is an arithmetic number, because the mean of its divisors is an integer number (260765626).

Almost surely, 2^521531251 is an apocalyptic number.

521531251 is a deficient number, since it is larger than the sum of its proper divisors (1).

521531251 is an equidigital number, since it uses as much as digits as its factorization.

521531251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1500, while the sum is 25.

The square root of 521531251 is about 22837.0587204219. The cubic root of 521531251 is about 804.9337038879.

Adding to 521531251 its reverse (152135125), we get a palindrome (673666376).

The spelling of 521531251 in words is "five hundred twenty-one million, five hundred thirty-one thousand, two hundred fifty-one".