26661605 has 4 divisors (see below), whose sum is σ = 31993932. Its totient is φ = 21329280.

The previous prime is 26661601. The next prime is 26661611. The reversal of 26661605 is 50616662.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50616662 = 2 ⋅25308331.

It can be written as a sum of positive squares in 2 ways, for example, as 15358561 + 11303044 = 3919^2 + 3362^2 .

It is not a de Polignac number, because 26661605 - 2² = 26661601 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 3 ways as a sum of consecutive naturals, for example, 2666156 + ... + 2666165.

It is an arithmetic number, because the mean of its divisors is an integer number (7998483).

Almost surely, 2^26661605 is an apocalyptic number.

It is an amenable number.

26661605 is a deficient number, since it is larger than the sum of its proper divisors (5332327).

26661605 is an equidigital number, since it uses as much as digits as its factorization.

26661605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5332326.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 26661605 is about 5163.4876779169. The cubic root of 26661605 is about 298.7414124268.

The spelling of 26661605 in words is "twenty-six million, six hundred sixty-one thousand, six hundred five".