25216643 has 4 divisors (see below), whose sum is σ = 25241688. Its totient is φ = 25191600.

The previous prime is 25216613. The next prime is 25216657. The reversal of 25216643 is 34661252.

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 25216643 - 2¹⁶ = 25151107 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25216613) 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, 10946 + ... + 13047.

It is an arithmetic number, because the mean of its divisors is an integer number (6310422).

Almost surely, 2^25216643 is an apocalyptic number.

25216643 is a deficient number, since it is larger than the sum of its proper divisors (25045).

25216643 is a wasteful number, since it uses less digits than its factorization.

25216643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25044.

The product of its digits is 8640, while the sum is 29.

The square root of 25216643 is about 5021.6175680751. The cubic root of 25216643 is about 293.2439697078.

Adding to 25216643 its reverse (34661252), we get a palindrome (59877895).

The spelling of 25216643 in words is "twenty-five million, two hundred sixteen thousand, six hundred forty-three".