521402540 has 12 divisors (see below), whose sum is σ = 1094945376. Its totient is φ = 208561008.

The previous prime is 521402527. The next prime is 521402561. The reversal of 521402540 is 45204125.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13035044 + ... + 13035083.

It is an arithmetic number, because the mean of its divisors is an integer number (91245448).

Almost surely, 2^521402540 is an apocalyptic number.

It is an amenable number.

521402540 is an abundant number, since it is smaller than the sum of its proper divisors (573542836).

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

521402540 is a wasteful number, since it uses less digits than its factorization.

521402540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26070136 (or 26070134 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 23.

The square root of 521402540 is about 22834.2405172583. The cubic root of 521402540 is about 804.8674807256.

Adding to 521402540 its reverse (45204125), we get a palindrome (566606665).

The spelling of 521402540 in words is "five hundred twenty-one million, four hundred two thousand, five hundred forty".