531621 has 6 divisors (see below), whose sum is σ = 767910. Its totient is φ = 354408.

The previous prime is 531613. The next prime is 531623. The reversal of 531621 is 126135.

It can be written as a sum of positive squares in only one way, i.e., 497025 + 34596 = 705^2 + 186^2 .

It is not a de Polignac number, because 531621 - 2³ = 531613 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 531594 and 531603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (531623) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 29526 + ... + 29543.

It is an arithmetic number, because the mean of its divisors is an integer number (127985).

2⁵³¹⁶²¹ is an apocalyptic number.

It is an amenable number.

531621 is a deficient number, since it is larger than the sum of its proper divisors (236289).

531621 is a wasteful number, since it uses less digits than its factorization.

531621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59075 (or 59072 counting only the distinct ones).

The product of its digits is 180, while the sum is 18.

The square root of 531621 is about 729.1234463381. The cubic root of 531621 is about 81.0091439151.

Subtracting from 531621 its product of digits (180), we obtain a 12-th power (531441 = 3¹²).

Adding to 531621 its reverse (126135), we get a palindrome (657756).

It can be divided in two parts, 5 and 31621, that added together give a triangular number (31626 = T₂₅₁).

The spelling of 531621 in words is "five hundred thirty-one thousand, six hundred twenty-one".