25641981446 has 4 divisors (see below), whose sum is σ = 38462972172. Its totient is φ = 12820990722.

The previous prime is 25641981413. The next prime is 25641981481. The reversal of 25641981446 is 64418914652.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×25641981446² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 25641981394 and 25641981403.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6410495360 + ... + 6410495363.

It is an arithmetic number, because the mean of its divisors is an integer number (9615743043).

Almost surely, 2^25641981446 is an apocalyptic number.

25641981446 is a deficient number, since it is larger than the sum of its proper divisors (12820990726).

25641981446 is a wasteful number, since it uses less digits than its factorization.

25641981446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12820990725.

The product of its digits is 1658880, while the sum is 50.

The spelling of 25641981446 in words is "twenty-five billion, six hundred forty-one million, nine hundred eighty-one thousand, four hundred forty-six".