25405643 has 4 divisors (see below), whose sum is σ = 26092320. Its totient is φ = 24718968.

The previous prime is 25405637. The next prime is 25405661. The reversal of 25405643 is 34650452.

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 25405643 - 2²² = 21211339 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25405693) 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, 343283 + ... + 343356.

It is an arithmetic number, because the mean of its divisors is an integer number (6523080).

Almost surely, 2^25405643 is an apocalyptic number.

25405643 is a deficient number, since it is larger than the sum of its proper divisors (686677).

25405643 is an equidigital number, since it uses as much as digits as its factorization.

25405643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 686676.

The product of its (nonzero) digits is 14400, while the sum is 29.

The square root of 25405643 is about 5040.4010753114. The cubic root of 25405643 is about 293.9747730063.

The spelling of 25405643 in words is "twenty-five million, four hundred five thousand, six hundred forty-three".