521990 has 16 divisors (see below), whose sum is σ = 1073952. Its totient is φ = 178944.

The previous prime is 521981. The next prime is 521993. The reversal of 521990 is 99125.

It is a happy number.

It is a Curzon number.

It is a nialpdrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521993) by changing a digit.

521990 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3659 + ... + 3798.

It is an arithmetic number, because the mean of its divisors is an integer number (67122).

2⁵²¹⁹⁹⁰ is an apocalyptic number.

521990 is an abundant number, since it is smaller than the sum of its proper divisors (551962).

It is a weird number, because it is abundant, but not a pseudoperfect number.

521990 is a wasteful number, since it uses less digits than its factorization.

521990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7471.

The product of its (nonzero) digits is 810, while the sum is 26.

The square root of 521990 is about 722.4887542377. The cubic root of 521990 is about 80.5169646486.

The spelling of 521990 in words is "five hundred twenty-one thousand, nine hundred ninety".