25772781 has 16 divisors (see below), whose sum is σ = 35351360. Its totient is φ = 16692480.

The previous prime is 25772777. The next prime is 25772783. The reversal of 25772781 is 18727752.

It is not a de Polignac number, because 25772781 - 2² = 25772777 is a prime.

It is a super-2 number, since 2×25772781² = 1328472480947922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25772783) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30675 + ... + 31503.

It is an arithmetic number, because the mean of its divisors is an integer number (2209460).

Almost surely, 2^25772781 is an apocalyptic number.

It is an amenable number.

25772781 is a deficient number, since it is larger than the sum of its proper divisors (9578579).

25772781 is a wasteful number, since it uses less digits than its factorization.

25772781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1116.

The product of its digits is 54880, while the sum is 39.

The square root of 25772781 is about 5076.6899649279. The cubic root of 25772781 is about 295.3840865114.

The spelling of 25772781 in words is "twenty-five million, seven hundred seventy-two thousand, seven hundred eighty-one".