521901 has 12 divisors (see below), whose sum is σ = 762528. Its totient is φ = 343944.

The previous prime is 521897. The next prime is 521903. The reversal of 521901 is 109125.

It is not a de Polignac number, because 521901 - 2² = 521897 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521903) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 646 + ... + 1208.

It is an arithmetic number, because the mean of its divisors is an integer number (63544).

2⁵²¹⁹⁰¹ is an apocalyptic number.

It is an amenable number.

521901 is a deficient number, since it is larger than the sum of its proper divisors (240627).

521901 is a wasteful number, since it uses less digits than its factorization.

521901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 672 (or 669 counting only the distinct ones).

The product of its (nonzero) digits is 90, while the sum is 18.

The square root of 521901 is about 722.4271589579. The cubic root of 521901 is about 80.5123883047.

It can be divided in two parts, 52 and 1901, that added together give a triangular number (1953 = T₆₂).

The spelling of 521901 in words is "five hundred twenty-one thousand, nine hundred one".