25721766 has 48 divisors (see below), whose sum is σ = 66498480. Its totient is φ = 7348320.

The previous prime is 25721747. The next prime is 25721767. The reversal of 25721766 is 66712752.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 25721766.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25721767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2215 + ... + 7506.

It is an arithmetic number, because the mean of its divisors is an integer number (1385385).

Almost surely, 2^25721766 is an apocalyptic number.

25721766 is an abundant number, since it is smaller than the sum of its proper divisors (40776714).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

25721766 is a wasteful number, since it uses less digits than its factorization.

25721766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9746 (or 9733 counting only the distinct ones).

The product of its digits is 35280, while the sum is 36.

The square root of 25721766 is about 5071.6630408575. The cubic root of 25721766 is about 295.1890619914.

The spelling of 25721766 in words is "twenty-five million, seven hundred twenty-one thousand, seven hundred sixty-six".