20997701 has 2 divisors, whose sum is σ = 20997702. Its totient is φ = 20997700.

The previous prime is 20997659. The next prime is 20997709. The reversal of 20997701 is 10779902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17850625 + 3147076 = 4225^2 + 1774^2 .

It is a cyclic number.

It is not a de Polignac number, because 20997701 - 2⁶ = 20997637 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 (20997709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10498850 + 10498851.

It is an arithmetic number, because the mean of its divisors is an integer number (10498851).

Almost surely, 2^20997701 is an apocalyptic number.

It is an amenable number.

20997701 is a deficient number, since it is larger than the sum of its proper divisors (1).

20997701 is an equidigital number, since it uses as much as digits as its factorization.

20997701 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7938, while the sum is 35.

The square root of 20997701 is about 4582.3248466253. The cubic root of 20997701 is about 275.8823493871.

The spelling of 20997701 in words is "twenty million, nine hundred ninety-seven thousand, seven hundred one".