25555530 has 256 divisors, whose sum is σ = 88252416. Its totient is φ = 4561920.

The previous prime is 25555529. The next prime is 25555531. The reversal of 25555530 is 3555552.

It is an interprime number because it is at equal distance from previous prime (25555529) and next prime (25555531).

It is a super-2 number, since 2×25555530² = 1306170227161800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (25555531) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 690672 + ... + 690708.

It is an arithmetic number, because the mean of its divisors is an integer number (344736).

Almost surely, 2^25555530 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25555530, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44126208).

25555530 is an abundant number, since it is smaller than the sum of its proper divisors (62696886).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

25555530 is a wasteful number, since it uses less digits than its factorization.

25555530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101.

The product of its (nonzero) digits is 18750, while the sum is 30.

The square root of 25555530 is about 5055.2477684086. The cubic root of 25555530 is about 294.5517658961.

It can be divided in two parts, 25 and 555530, that added together give a palindrome (555555).

The spelling of 25555530 in words is "twenty-five million, five hundred fifty-five thousand, five hundred thirty".