21069791 has 2 divisors, whose sum is σ = 21069792. Its totient is φ = 21069790.

The previous prime is 21069781. The next prime is 21069833. The reversal of 21069791 is 19796012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21069791 - 2²² = 16875487 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21069701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10534895 + 10534896.

It is an arithmetic number, because the mean of its divisors is an integer number (10534896).

Almost surely, 2^21069791 is an apocalyptic number.

21069791 is a deficient number, since it is larger than the sum of its proper divisors (1).

21069791 is an equidigital number, since it uses as much as digits as its factorization.

21069791 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6804, while the sum is 35.

The square root of 21069791 is about 4590.1842010969. The cubic root of 21069791 is about 276.1977115534.

The spelling of 21069791 in words is "twenty-one million, sixty-nine thousand, seven hundred ninety-one".