25621553 has 4 divisors (see below), whose sum is σ = 25641588. Its totient is φ = 25601520.

The previous prime is 25621549. The next prime is 25621571. The reversal of 25621553 is 35512652.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15272464 + 10349089 = 3908^2 + 3217^2 .

It is a cyclic number.

It is not a de Polignac number, because 25621553 - 2² = 25621549 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25621513) 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, 7958 + ... + 10703.

It is an arithmetic number, because the mean of its divisors is an integer number (6410397).

Almost surely, 2^25621553 is an apocalyptic number.

It is an amenable number.

25621553 is a deficient number, since it is larger than the sum of its proper divisors (20035).

25621553 is a wasteful number, since it uses less digits than its factorization.

25621553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20034.

The product of its digits is 9000, while the sum is 29.

The square root of 25621553 is about 5061.7737009866. The cubic root of 25621553 is about 294.8052070351.

The spelling of 25621553 in words is "twenty-five million, six hundred twenty-one thousand, five hundred fifty-three".