521669489 has 4 divisors (see below), whose sum is σ = 569094000. Its totient is φ = 474244980.

The previous prime is 521669471. The next prime is 521669501. The reversal of 521669489 is 984966125.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a de Polignac number, because none of the positive numbers 2^k-521669489 is a prime.

It is a super-2 number, since 2×521669489² = 544278111507042242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (521669419) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23712239 + ... + 23712260.

It is an arithmetic number, because the mean of its divisors is an integer number (142273500).

Almost surely, 2^521669489 is an apocalyptic number.

It is an amenable number.

521669489 is a deficient number, since it is larger than the sum of its proper divisors (47424511).

521669489 is a wasteful number, since it uses less digits than its factorization.

521669489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47424510.

The product of its digits is 933120, while the sum is 50.

The square root of 521669489 is about 22840.0851355681. The cubic root of 521669489 is about 805.0048166578.

The spelling of 521669489 in words is "five hundred twenty-one million, six hundred sixty-nine thousand, four hundred eighty-nine".