25347991 has 4 divisors (see below), whose sum is σ = 25594192. Its totient is φ = 25101792.

The previous prime is 25347977. The next prime is 25348007. The reversal of 25347991 is 19974352.

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 25347991 - 2¹³ = 25339799 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25347911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122946 + ... + 123151.

It is an arithmetic number, because the mean of its divisors is an integer number (6398548).

Almost surely, 2^25347991 is an apocalyptic number.

25347991 is a deficient number, since it is larger than the sum of its proper divisors (246201).

25347991 is a wasteful number, since it uses less digits than its factorization.

25347991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246200.

The product of its digits is 68040, while the sum is 40.

The square root of 25347991 is about 5034.6788378207. The cubic root of 25347991 is about 293.7522362286.

The spelling of 25347991 in words is "twenty-five million, three hundred forty-seven thousand, nine hundred ninety-one".