26661661 has 8 divisors (see below), whose sum is σ = 30401784. Its totient is φ = 23162880.

The previous prime is 26661647. The next prime is 26661683. The reversal of 26661661 is 16616662.

It can be written as a sum of positive squares in 4 ways, for example, as 6859161 + 19802500 = 2619^2 + 4450^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 26661661 - 2⁵ = 26661629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26661601) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60100 + ... + 60541.

It is an arithmetic number, because the mean of its divisors is an integer number (3800223).

Almost surely, 2^26661661 is an apocalyptic number.

It is an amenable number.

26661661 is a deficient number, since it is larger than the sum of its proper divisors (3740123).

26661661 is a wasteful number, since it uses less digits than its factorization.

26661661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120671.

The product of its digits is 15552, while the sum is 34.

The square root of 26661661 is about 5163.4931006054. The cubic root of 26661661 is about 298.7416215854.

The spelling of 26661661 in words is "twenty-six million, six hundred sixty-one thousand, six hundred sixty-one".