20970709 has 2 divisors, whose sum is σ = 20970710. Its totient is φ = 20970708.

The previous prime is 20970701. The next prime is 20970739. The reversal of 20970709 is 90707902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20295025 + 675684 = 4505^2 + 822^2 .

It is a cyclic number.

It is not a de Polignac number, because 20970709 - 2³ = 20970701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20970701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10485354 + 10485355.

It is an arithmetic number, because the mean of its divisors is an integer number (10485355).

Almost surely, 2^20970709 is an apocalyptic number.

It is an amenable number.

20970709 is a deficient number, since it is larger than the sum of its proper divisors (1).

20970709 is an equidigital number, since it uses as much as digits as its factorization.

20970709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7938, while the sum is 34.

The square root of 20970709 is about 4579.3786696450. The cubic root of 20970709 is about 275.7640854961.

The spelling of 20970709 in words is "twenty million, nine hundred seventy thousand, seven hundred nine".