521412309 has 20 divisors (see below), whose sum is σ = 849710400. Its totient is φ = 316006920.

The previous prime is 521412299. The next prime is 521412317. The reversal of 521412309 is 903214125.

It is not a de Polignac number, because 521412309 - 2⁷ = 521412181 is a prime.

It is a super-2 number, since 2×521412309² = 543741591953422962, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521412319) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 291709 + ... + 293490.

It is an arithmetic number, because the mean of its divisors is an integer number (42485520).

Almost surely, 2^521412309 is an apocalyptic number.

It is an amenable number.

521412309 is a deficient number, since it is larger than the sum of its proper divisors (328298091).

521412309 is a wasteful number, since it uses less digits than its factorization.

521412309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 585222 (or 585213 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 521412309 is about 22834.4544274655. The cubic root of 521412309 is about 804.8725073610.

The spelling of 521412309 in words is "five hundred twenty-one million, four hundred twelve thousand, three hundred nine".