520409639 has 8 divisors (see below), whose sum is σ = 550641840. Its totient is φ = 490461696.

The previous prime is 520409621. The next prime is 520409647. The reversal of 520409639 is 936904025.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-520409639 is a prime.

It is a super-2 number, since 2×520409639² = 541652384728220642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (520409689) 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, 67292 + ... + 74625.

It is an arithmetic number, because the mean of its divisors is an integer number (68830230).

Almost surely, 2^520409639 is an apocalyptic number.

520409639 is a deficient number, since it is larger than the sum of its proper divisors (30232201).

520409639 is a wasteful number, since it uses less digits than its factorization.

520409639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142129.

The product of its (nonzero) digits is 58320, while the sum is 38.

The square root of 520409639 is about 22812.4886630109. The cubic root of 520409639 is about 804.3562560475.

The spelling of 520409639 in words is "five hundred twenty million, four hundred nine thousand, six hundred thirty-nine".