26661281 has 4 divisors (see below), whose sum is σ = 27036864. Its totient is φ = 26285700.

The previous prime is 26661259. The next prime is 26661289. The reversal of 26661281 is 18216662.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18216662 = 2 ⋅9108331.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-26661281 is a prime.

It is a super-2 number, since 2×26661281² = 1421647809121922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (26661289) 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, 187685 + ... + 187826.

It is an arithmetic number, because the mean of its divisors is an integer number (6759216).

Almost surely, 2^26661281 is an apocalyptic number.

It is an amenable number.

26661281 is a deficient number, since it is larger than the sum of its proper divisors (375583).

26661281 is an equidigital number, since it uses as much as digits as its factorization.

26661281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 375582.

The product of its digits is 6912, while the sum is 32.

The square root of 26661281 is about 5163.4563036788. The cubic root of 26661281 is about 298.7402022895.

The spelling of 26661281 in words is "twenty-six million, six hundred sixty-one thousand, two hundred eighty-one".