521890964 has 42 divisors (see below), whose sum is σ = 1066486890. Its totient is φ = 223465872.

The previous prime is 521890949. The next prime is 521891017. The reversal of 521890964 is 469098125.

It can be written as a sum of positive squares in only one way, i.e., 294122500 + 227768464 = 17150^2 + 15092^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 470042 + ... + 471150.

It is an arithmetic number, because the mean of its divisors is an integer number (25392545).

Almost surely, 2^521890964 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 521890964, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (533243445).

521890964 is an abundant number, since it is smaller than the sum of its proper divisors (544595926).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

521890964 is an frugal number, since it uses more digits than its factorization.

521890964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1155 (or 1118 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 44.

The square root of 521890964 is about 22844.9330049357. The cubic root of 521890964 is about 805.1187222504.

The spelling of 521890964 in words is "five hundred twenty-one million, eight hundred ninety thousand, nine hundred sixty-four".