521665131 has 8 divisors (see below), whose sum is σ = 749057680. Its totient is φ = 321024672.

The previous prime is 521665091. The next prime is 521665141. The reversal of 521665131 is 131566125.

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

It is not a de Polignac number, because 521665131 - 2⁷ = 521665003 is a prime.

It is a super-2 number, since 2×521665131² = 544269017802494322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (521665141) 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, 6687976 + ... + 6688053.

It is an arithmetic number, because the mean of its divisors is an integer number (93632210).

Almost surely, 2^521665131 is an apocalyptic number.

521665131 is a deficient number, since it is larger than the sum of its proper divisors (227392549).

521665131 is a wasteful number, since it uses less digits than its factorization.

521665131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13376045.

The product of its digits is 5400, while the sum is 30.

The square root of 521665131 is about 22839.9897329224. The cubic root of 521665131 is about 805.0025749953.

The spelling of 521665131 in words is "five hundred twenty-one million, six hundred sixty-five thousand, one hundred thirty-one".