26521721 has 2 divisors, whose sum is σ = 26521722. Its totient is φ = 26521720.

The previous prime is 26521699. The next prime is 26521757. The reversal of 26521721 is 12712562.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16687225 + 9834496 = 4085^2 + 3136^2 .

It is a cyclic number.

It is not a de Polignac number, because 26521721 - 2⁶ = 26521657 is a prime.

It is a Chen prime.

It is a weakly prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13260860 + 13260861.

It is an arithmetic number, because the mean of its divisors is an integer number (13260861).

Almost surely, 2^26521721 is an apocalyptic number.

It is an amenable number.

26521721 is a deficient number, since it is larger than the sum of its proper divisors (1).

26521721 is an equidigital number, since it uses as much as digits as its factorization.

26521721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1680, while the sum is 26.

The square root of 26521721 is about 5149.9243683767. The cubic root of 26521721 is about 298.2180325604.

The spelling of 26521721 in words is "twenty-six million, five hundred twenty-one thousand, seven hundred twenty-one".