521312540 has 48 divisors (see below), whose sum is σ = 1281680064. Its totient is φ = 174374400.

The previous prime is 521312513. The next prime is 521312587. The reversal of 521312540 is 45213125.

It is a super-2 number, since 2×521312540² = 543533528722503200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39671 + ... + 51150.

It is an arithmetic number, because the mean of its divisors is an integer number (26701668).

Almost surely, 2^521312540 is an apocalyptic number.

It is an amenable number.

521312540 is an abundant number, since it is smaller than the sum of its proper divisors (760367524).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

521312540 is a wasteful number, since it uses less digits than its factorization.

521312540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90878 (or 90876 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 521312540 is about 22832.2697075871. The cubic root of 521312540 is about 804.8211683048.

Adding to 521312540 its reverse (45213125), we get a palindrome (566525665).

The spelling of 521312540 in words is "five hundred twenty-one million, three hundred twelve thousand, five hundred forty".