25721000 has 96 divisors (see below), whose sum is σ = 64654200. Its totient is φ = 9574400.

The previous prime is 25720993. The next prime is 25721011. The reversal of 25721000 is 12752.

It can be written as a sum of positive squares in 12 ways, for example, as 178084 + 25542916 = 422^2 + 5054^2 .

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a self number, because there is not a number n which added to its sum of digits gives 25721000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 288956 + ... + 289044.

Almost surely, 2^25721000 is an apocalyptic number.

25721000 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 25721000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32327100).

25721000 is an abundant number, since it is smaller than the sum of its proper divisors (38933200).

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

25721000 is a wasteful number, since it uses less digits than its factorization.

25721000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144 (or 113 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 17.

The square root of 25721000 is about 5071.5875226599. The cubic root of 25721000 is about 295.1861316967.

Adding to 25721000 its reverse (12752), we get a palindrome (25733752).

The spelling of 25721000 in words is "twenty-five million, seven hundred twenty-one thousand".