25691280 has 80 divisors (see below), whose sum is σ = 80244864. Its totient is φ = 6799360.

The previous prime is 25691261. The next prime is 25691293. The reversal of 25691280 is 8219652.

It is a tau number, because it is divible by the number of its divisors (80).

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, 39760 + ... + 40400.

Almost surely, 2^25691280 is an apocalyptic number.

25691280 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 25691280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40122432).

25691280 is an abundant number, since it is smaller than the sum of its proper divisors (54553584).

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

25691280 is a wasteful number, since it uses less digits than its factorization.

25691280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 824 (or 818 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 33.

The square root of 25691280 is about 5068.6566267602. The cubic root of 25691280 is about 295.0723943747.

The spelling of 25691280 in words is "twenty-five million, six hundred ninety-one thousand, two hundred eighty".