520649409 has 16 divisors (see below), whose sum is σ = 810252288. Its totient is φ = 291183312.

The previous prime is 520649407. The next prime is 520649491. The reversal of 520649409 is 904946025.

It is not a de Polignac number, because 520649409 - 2¹ = 520649407 is a prime.

It is not an unprimeable number, because it can be changed into a prime (520649401) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 262767 + ... + 264740.

It is an arithmetic number, because the mean of its divisors is an integer number (50640768).

Almost surely, 2^520649409 is an apocalyptic number.

It is an amenable number.

520649409 is a deficient number, since it is larger than the sum of its proper divisors (289602879).

520649409 is a wasteful number, since it uses less digits than its factorization.

520649409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 527564.

The product of its (nonzero) digits is 77760, while the sum is 39.

The square root of 520649409 is about 22817.7432933233. The cubic root of 520649409 is about 804.4797682922.

It can be divided in two parts, 5206 and 49409, that added together give a triangular number (54615 = T₃₃₀).

The spelling of 520649409 in words is "five hundred twenty million, six hundred forty-nine thousand, four hundred nine".