25724220394 has 4 divisors (see below), whose sum is σ = 38586330594. Its totient is φ = 12862110196.

The previous prime is 25724220383. The next prime is 25724220409. The reversal of 25724220394 is 49302242752.

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., 18218250625 + 7505969769 = 134975^2 + 86637^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6431055097 + ... + 6431055100.

Almost surely, 2^25724220394 is an apocalyptic number.

25724220394 is a deficient number, since it is larger than the sum of its proper divisors (12862110200).

25724220394 is a wasteful number, since it uses less digits than its factorization.

25724220394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12862110199.

The product of its (nonzero) digits is 241920, while the sum is 40.

The spelling of 25724220394 in words is "twenty-five billion, seven hundred twenty-four million, two hundred twenty thousand, three hundred ninety-four".