26666621 has 2 divisors, whose sum is σ = 26666622. Its totient is φ = 26666620.

The previous prime is 26666611. The next prime is 26666663. The reversal of 26666621 is 12666662.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20839225 + 5827396 = 4565^2 + 2414^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-26666621 is a prime.

It is a super-2 number, since 2×26666621² = 1422217351115282, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26666611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13333310 + 13333311.

It is an arithmetic number, because the mean of its divisors is an integer number (13333311).

Almost surely, 2^26666621 is an apocalyptic number.

It is an amenable number.

26666621 is a deficient number, since it is larger than the sum of its proper divisors (1).

26666621 is an equidigital number, since it uses as much as digits as its factorization.

26666621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 35.

The square root of 26666621 is about 5163.9733732853. The cubic root of 26666621 is about 298.7601458947.

The spelling of 26666621 in words is "twenty-six million, six hundred sixty-six thousand, six hundred twenty-one".