253621 has 4 divisors (see below), whose sum is σ = 264672. Its totient is φ = 242572.

The previous prime is 253613. The next prime is 253633. The reversal of 253621 is 126352.

It is a happy number.

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 253621 - 2³ = 253613 is a prime.

It is a super-2 number, since 2×253621² = 128647223282, which contains 22 as substring.

It is a Duffinian number.

253621 is a modest number, since divided by 621 gives 253 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (253601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5491 + ... + 5536.

It is an arithmetic number, because the mean of its divisors is an integer number (66168).

2²⁵³⁶²¹ is an apocalyptic number.

It is an amenable number.

253621 is a deficient number, since it is larger than the sum of its proper divisors (11051).

253621 is a wasteful number, since it uses less digits than its factorization.

253621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11050.

The product of its digits is 360, while the sum is 19.

The square root of 253621 is about 503.6079824625. The cubic root of 253621 is about 63.2987407273.

Adding to 253621 its reverse (126352), we get a palindrome (379973).

It can be divided in two parts, 25 and 3621, that multiplied together give a triangular number (90525 = T₄₂₅).

The spelling of 253621 in words is "two hundred fifty-three thousand, six hundred twenty-one".