25515000 has 280 divisors, whose sum is σ = 102435960. Its totient is φ = 5832000.

The previous prime is 25514989. The next prime is 25515029. The reversal of 25515000 is 51552.

It is a tau number, because it is divible by the number of its divisors (280).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

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 69 ways as a sum of consecutive naturals, for example, 3644997 + ... + 3645003.

Almost surely, 2^25515000 is an apocalyptic number.

25515000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25515000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51217980).

25515000 is an abundant number, since it is smaller than the sum of its proper divisors (76920960).

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

25515000 is an frugal number, since it uses more digits than its factorization.

25515000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51 (or 17 counting only the distinct ones).

The product of its (nonzero) digits is 250, while the sum is 18.

The square root of 25515000 is about 5051.2374721448. The cubic root of 25515000 is about 294.3959679170.

Adding to 25515000 its reverse (51552), we get a palindrome (25566552).

The spelling of 25515000 in words is "twenty-five million, five hundred fifteen thousand".