25640578 has 4 divisors (see below), whose sum is σ = 38460870. Its totient is φ = 12820288.

The previous prime is 25640543. The next prime is 25640579. The reversal of 25640578 is 87504652.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 15547249 + 10093329 = 3943^2 + 3177^2 .

It is not an unprimeable number, because it can be changed into a prime (25640579) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6410143 + ... + 6410146.

Almost surely, 2^25640578 is an apocalyptic number.

25640578 is a deficient number, since it is larger than the sum of its proper divisors (12820292).

25640578 is a wasteful number, since it uses less digits than its factorization.

25640578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12820291.

The product of its (nonzero) digits is 67200, while the sum is 37.

The square root of 25640578 is about 5063.6526342157. The cubic root of 25640578 is about 294.8781570942.

The spelling of 25640578 in words is "twenty-five million, six hundred forty thousand, five hundred seventy-eight".