25809780 has 48 divisors (see below), whose sum is σ = 72777600. Its totient is φ = 6834048.

The previous prime is 25809767. The next prime is 25809811. The reversal of 25809780 is 8790852.

It is a super-2 number, since 2×25809780² = 1332289487296800, which contains 22 as substring.

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 15 ways as a sum of consecutive naturals, for example, 7497 + ... + 10383.

It is an arithmetic number, because the mean of its divisors is an integer number (1516200).

Almost surely, 2^25809780 is an apocalyptic number.

25809780 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 25809780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36388800).

25809780 is an abundant number, since it is smaller than the sum of its proper divisors (46967820).

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

25809780 is a wasteful number, since it uses less digits than its factorization.

25809780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3048 (or 3046 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 39.

The square root of 25809780 is about 5080.3326662729. The cubic root of 25809780 is about 295.5253685121.

The spelling of 25809780 in words is "twenty-five million, eight hundred nine thousand, seven hundred eighty".