521256342634 has 16 divisors (see below), whose sum is σ = 827932389768. Its totient is φ = 245280904192.

The previous prime is 521256342623. The next prime is 521256342637. The reversal of 521256342634 is 436243652125.

It can be written as a sum of positive squares in 4 ways, for example, as 494328517225 + 26927825409 = 703085^2 + 164097^2 .

It is not an unprimeable number, because it can be changed into a prime (521256342637) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24312 + ... + 1021324.

Almost surely, 2^521256342634 is an apocalyptic number.

521256342634 is a deficient number, since it is larger than the sum of its proper divisors (306676047134).

521256342634 is a wasteful number, since it uses less digits than its factorization.

521256342634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1012409.

The product of its digits is 1036800, while the sum is 43.

Adding to 521256342634 its reverse (436243652125), we get a palindrome (957499994759).

The spelling of 521256342634 in words is "five hundred twenty-one billion, two hundred fifty-six million, three hundred forty-two thousand, six hundred thirty-four".