25492781 has 4 divisors (see below), whose sum is σ = 25605312. Its totient is φ = 25380252.

The previous prime is 25492777. The next prime is 25492783. The reversal of 25492781 is 18729452.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 25492781 - 2² = 25492777 is a prime.

It is a super-2 number, since 2×25492781² = 1299763766227922, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25492783) 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, 55925 + ... + 56378.

It is an arithmetic number, because the mean of its divisors is an integer number (6401328).

Almost surely, 2^25492781 is an apocalyptic number.

It is an amenable number.

25492781 is a deficient number, since it is larger than the sum of its proper divisors (112531).

25492781 is a wasteful number, since it uses less digits than its factorization.

25492781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112530.

The product of its digits is 40320, while the sum is 38.

The square root of 25492781 is about 5049.0376310739. The cubic root of 25492781 is about 294.3104876940.

The spelling of 25492781 in words is "twenty-five million, four hundred ninety-two thousand, seven hundred eighty-one".