25553661 has 8 divisors (see below), whose sum is σ = 38938944. Its totient is φ = 14602080.

The previous prime is 25553659. The next prime is 25553663. The reversal of 25553661 is 16635552.

It is an interprime number because it is at equal distance from previous prime (25553659) and next prime (25553663).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 25553661 - 2¹ = 25553659 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25553663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 608400 + ... + 608441.

It is an arithmetic number, because the mean of its divisors is an integer number (4867368).

Almost surely, 2^25553661 is an apocalyptic number.

25553661 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

25553661 is a deficient number, since it is larger than the sum of its proper divisors (13385283).

25553661 is a wasteful number, since it uses less digits than its factorization.

25553661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1216851.

The product of its digits is 27000, while the sum is 33.

The square root of 25553661 is about 5055.0629076204. The cubic root of 25553661 is about 294.5445850541.

It can be divided in two parts, 2555 and 3661, that added together give a triangular number (6216 = T₁₁₁).

The spelling of 25553661 in words is "twenty-five million, five hundred fifty-three thousand, six hundred sixty-one".