25305597691 has 12 divisors (see below), whose sum is σ = 28075213656. Its totient is φ = 22790076320.

The previous prime is 25305597689. The next prime is 25305597703. The reversal of 25305597691 is 19679550352.

It is not a de Polignac number, because 25305597691 - 2¹ = 25305597689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25305597661) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 964330 + ... + 990223.

It is an arithmetic number, because the mean of its divisors is an integer number (2339601138).

Almost surely, 2^25305597691 is an apocalyptic number.

25305597691 is a deficient number, since it is larger than the sum of its proper divisors (2769615965).

25305597691 is a wasteful number, since it uses less digits than its factorization.

25305597691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1954682 (or 1954671 counting only the distinct ones).

The product of its (nonzero) digits is 2551500, while the sum is 52.

The spelling of 25305597691 in words is "twenty-five billion, three hundred five million, five hundred ninety-seven thousand, six hundred ninety-one".