25405681 has 8 divisors (see below), whose sum is σ = 29099520. Its totient is φ = 21727968.

The previous prime is 25405661. The next prime is 25405693. The reversal of 25405681 is 18650452.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 25405681 - 2¹⁷ = 25274609 is a prime.

It is a super-2 number, since 2×25405681² = 1290897254147522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25405631) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 436 + ... + 7141.

It is an arithmetic number, because the mean of its divisors is an integer number (3637440).

Almost surely, 2^25405681 is an apocalyptic number.

It is an amenable number.

25405681 is a deficient number, since it is larger than the sum of its proper divisors (3693839).

25405681 is an equidigital number, since it uses as much as digits as its factorization.

25405681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8063.

The product of its (nonzero) digits is 9600, while the sum is 31.

The square root of 25405681 is about 5040.4048448513. The cubic root of 25405681 is about 293.9749195752.

The spelling of 25405681 in words is "twenty-five million, four hundred five thousand, six hundred eighty-one".