25729227721 has 16 divisors (see below), whose sum is σ = 27449508240. Its totient is φ = 24070072320.

The previous prime is 25729227673. The next prime is 25729227737. The reversal of 25729227721 is 12772292752.

It can be written as a sum of positive squares in 8 ways, for example, as 4120227721 + 21609000000 = 64189^2 + 147000^2 .

It is a cyclic number.

It is not a de Polignac number, because 25729227721 - 2²³ = 25720839113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25729227761) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 208845 + ... + 308341.

It is an arithmetic number, because the mean of its divisors is an integer number (1715594265).

Almost surely, 2^25729227721 is an apocalyptic number.

It is an amenable number.

25729227721 is a deficient number, since it is larger than the sum of its proper divisors (1720280519).

25729227721 is a wasteful number, since it uses less digits than its factorization.

25729227721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99804.

The product of its digits is 493920, while the sum is 46.

The spelling of 25729227721 in words is "twenty-five billion, seven hundred twenty-nine million, two hundred twenty-seven thousand, seven hundred twenty-one".