2531621 has 4 divisors (see below), whose sum is σ = 2535744. Its totient is φ = 2527500.

The previous prime is 2531611. The next prime is 2531629. The reversal of 2531621 is 1261352.

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 cyclic number.

It is not a de Polignac number, because 2531621 - 2¹⁰ = 2530597 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2531593 and 2531602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2531629) 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, 935 + ... + 2436.

It is an arithmetic number, because the mean of its divisors is an integer number (633936).

2^2531621 is an apocalyptic number.

It is an amenable number.

2531621 is a deficient number, since it is larger than the sum of its proper divisors (4123).

2531621 is an equidigital number, since it uses as much as digits as its factorization.

2531621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4122.

The product of its digits is 360, while the sum is 20.

The square root of 2531621 is about 1591.1068474493. The cubic root of 2531621 is about 136.2907024259.

Adding to 2531621 its reverse (1261352), we get a palindrome (3792973).

It can be divided in two parts, 2531 and 621, that multiplied together give a palindrome (1571751).

The spelling of 2531621 in words is "two million, five hundred thirty-one thousand, six hundred twenty-one".