25780257 has 6 divisors (see below), whose sum is σ = 37238162. Its totient is φ = 17186832.

The previous prime is 25780241. The next prime is 25780277. The reversal of 25780257 is 75208752.

It can be written as a sum of positive squares in only one way, i.e., 25644096 + 136161 = 5064^2 + 369^2 .

It is not a de Polignac number, because 25780257 - 2⁴ = 25780241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25780277) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1432228 + ... + 1432245.

Almost surely, 2^25780257 is an apocalyptic number.

It is an amenable number.

25780257 is a deficient number, since it is larger than the sum of its proper divisors (11457905).

25780257 is a wasteful number, since it uses less digits than its factorization.

25780257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2864479 (or 2864476 counting only the distinct ones).

The product of its (nonzero) digits is 39200, while the sum is 36.

The square root of 25780257 is about 5077.4262180755. The cubic root of 25780257 is about 295.4126447792.

The spelling of 25780257 in words is "twenty-five million, seven hundred eighty thousand, two hundred fifty-seven".