26658661 has 2 divisors, whose sum is σ = 26658662. Its totient is φ = 26658660.

The previous prime is 26658659. The next prime is 26658673. The reversal of 26658661 is 16685662.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26522500 + 136161 = 5150^2 + 369^2 .

It is a cyclic number.

It is not a de Polignac number, because 26658661 - 2¹ = 26658659 is a prime.

Together with 26658659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26658641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13329330 + 13329331.

It is an arithmetic number, because the mean of its divisors is an integer number (13329331).

Almost surely, 2^26658661 is an apocalyptic number.

It is an amenable number.

26658661 is a deficient number, since it is larger than the sum of its proper divisors (1).

26658661 is an equidigital number, since it uses as much as digits as its factorization.

26658661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 40.

The square root of 26658661 is about 5163.2025914155. The cubic root of 26658661 is about 298.7304162510.

The spelling of 26658661 in words is "twenty-six million, six hundred fifty-eight thousand, six hundred sixty-one".