25861640 has 32 divisors (see below), whose sum is σ = 66502080. Its totient is φ = 8866752.

The previous prime is 25861553. The next prime is 25861643. The reversal of 25861640 is 4616852.

It is a junction number, because it is equal to n+sod(n) for n = 25861597 and 25861606.

It is not an unprimeable number, because it can be changed into a prime (25861643) 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, 45902 + ... + 46461.

It is an arithmetic number, because the mean of its divisors is an integer number (2078190).

Almost surely, 2^25861640 is an apocalyptic number.

25861640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25861640 is an abundant number, since it is smaller than the sum of its proper divisors (40640440).

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

25861640 is a wasteful number, since it uses less digits than its factorization.

25861640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92381 (or 92377 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 25861640 is about 5085.4341014313. The cubic root of 25861640 is about 295.7231706911.

The spelling of 25861640 in words is "twenty-five million, eight hundred sixty-one thousand, six hundred forty".