25720720771 has 4 divisors (see below), whose sum is σ = 26318877112. Its totient is φ = 25122564432.

The previous prime is 25720720769. The next prime is 25720720777. The reversal of 25720720771 is 17702702752.

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 25720720771 - 2¹ = 25720720769 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25720720777) 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, 299078106 + ... + 299078191.

It is an arithmetic number, because the mean of its divisors is an integer number (6579719278).

Almost surely, 2^25720720771 is an apocalyptic number.

25720720771 is a deficient number, since it is larger than the sum of its proper divisors (598156341).

25720720771 is an equidigital number, since it uses as much as digits as its factorization.

25720720771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 598156340.

The product of its (nonzero) digits is 96040, while the sum is 40.

The spelling of 25720720771 in words is "twenty-five billion, seven hundred twenty million, seven hundred twenty thousand, seven hundred seventy-one".