25582780778 has 4 divisors (see below), whose sum is σ = 38374171170. Its totient is φ = 12791390388.

The previous prime is 25582780747. The next prime is 25582780801. The reversal of 25582780778 is 87708728552.

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., 25522299049 + 60481729 = 159757^2 + 7777^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6395695193 + ... + 6395695196.

Almost surely, 2^25582780778 is an apocalyptic number.

25582780778 is a deficient number, since it is larger than the sum of its proper divisors (12791390392).

25582780778 is a wasteful number, since it uses less digits than its factorization.

25582780778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12791390391.

The product of its (nonzero) digits is 17561600, while the sum is 59.

The spelling of 25582780778 in words is "twenty-five billion, five hundred eighty-two million, seven hundred eighty thousand, seven hundred seventy-eight".