521613989 has 16 divisors (see below), whose sum is σ = 576098544. Its totient is φ = 469324800.

The previous prime is 521613977. The next prime is 521614007. The reversal of 521613989 is 989316125.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 173791489 + 347822500 = 13183^2 + 18650^2 .

It is a cyclic number.

It is not a de Polignac number, because 521613989 - 2²⁸ = 253178533 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521643989) 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, 86699 + ... + 92519.

It is an arithmetic number, because the mean of its divisors is an integer number (36006159).

Almost surely, 2^521613989 is an apocalyptic number.

It is an amenable number.

521613989 is a deficient number, since it is larger than the sum of its proper divisors (54484555).

521613989 is a wasteful number, since it uses less digits than its factorization.

521613989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6008.

The product of its digits is 116640, while the sum is 44.

The square root of 521613989 is about 22838.8701340500. The cubic root of 521613989 is about 804.9762677056.

The spelling of 521613989 in words is "five hundred twenty-one million, six hundred thirteen thousand, nine hundred eighty-nine".