25716661 has 8 divisors (see below), whose sum is σ = 26417664. Its totient is φ = 25022160.

The previous prime is 25716643. The next prime is 25716667. The reversal of 25716661 is 16661752.

It is a happy number.

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 25716661 - 2⁵ = 25716629 is a prime.

It is a super-2 number, since 2×25716661² = 1322693305977842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25716667) 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 7 ways as a sum of consecutive naturals, for example, 6996 + ... + 10018.

It is an arithmetic number, because the mean of its divisors is an integer number (3302208).

Almost surely, 2^25716661 is an apocalyptic number.

It is an amenable number.

25716661 is a deficient number, since it is larger than the sum of its proper divisors (701003).

25716661 is a wasteful number, since it uses less digits than its factorization.

25716661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3251.

The product of its digits is 15120, while the sum is 34.

The square root of 25716661 is about 5071.1597292927. The cubic root of 25716661 is about 295.1695319708.

The spelling of 25716661 in words is "twenty-five million, seven hundred sixteen thousand, six hundred sixty-one".