25571220 has 48 divisors (see below), whose sum is σ = 72679488. Its totient is φ = 6716160.

The previous prime is 25571219. The next prime is 25571257. The reversal of 25571220 is 2217552.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 840 + ... + 7200.

It is an arithmetic number, because the mean of its divisors is an integer number (1514156).

Almost surely, 2^25571220 is an apocalyptic number.

25571220 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 25571220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36339744).

25571220 is an abundant number, since it is smaller than the sum of its proper divisors (47108268).

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

25571220 is a wasteful number, since it uses less digits than its factorization.

25571220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6440 (or 6438 counting only the distinct ones).

The product of its (nonzero) digits is 1400, while the sum is 24.

The square root of 25571220 is about 5056.7993830090. The cubic root of 25571220 is about 294.6120342832.

Adding to 25571220 its reverse (2217552), we get a palindrome (27788772).

The spelling of 25571220 in words is "twenty-five million, five hundred seventy-one thousand, two hundred twenty".