521540004 has 24 divisors (see below), whose sum is σ = 1218753760. Its totient is φ = 173585664.

The previous prime is 521540003. The next prime is 521540023. The reversal of 521540004 is 400045125.

It is not an unprimeable number, because it can be changed into a prime (521540003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24214 + ... + 40365.

Almost surely, 2^521540004 is an apocalyptic number.

It is an amenable number.

521540004 is an abundant number, since it is smaller than the sum of its proper divisors (697213756).

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

521540004 is a wasteful number, since it uses less digits than its factorization.

521540004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65259 (or 65257 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 521540004 is about 22837.2503598835. The cubic root of 521540004 is about 804.9382070027.

Adding to 521540004 its reverse (400045125), we get a palindrome (921585129).

The spelling of 521540004 in words is "five hundred twenty-one million, five hundred forty thousand, four".