25291512779 has 4 divisors (see below), whose sum is σ = 27237013776. Its totient is φ = 23346011784.

The previous prime is 25291512671. The next prime is 25291512797. The reversal of 25291512779 is 97721519252.

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

It is a cyclic number.

It is not a de Polignac number, because 25291512779 - 2⁸ = 25291512523 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25291112779) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 972750479 + ... + 972750504.

It is an arithmetic number, because the mean of its divisors is an integer number (6809253444).

Almost surely, 2^25291512779 is an apocalyptic number.

25291512779 is a deficient number, since it is larger than the sum of its proper divisors (1945500997).

25291512779 is a wasteful number, since it uses less digits than its factorization.

25291512779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1945500996.

The product of its digits is 793800, while the sum is 50.

The spelling of 25291512779 in words is "twenty-five billion, two hundred ninety-one million, five hundred twelve thousand, seven hundred seventy-nine".