20993017 has 2 divisors, whose sum is σ = 20993018. Its totient is φ = 20993016.

The previous prime is 20993009. The next prime is 20993033. The reversal of 20993017 is 71039902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20034576 + 958441 = 4476^2 + 979^2 .

It is a cyclic number.

It is not a de Polignac number, because 20993017 - 2³ = 20993009 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20993017.

It is not a weakly prime, because it can be changed into another prime (20993047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10496508 + 10496509.

It is an arithmetic number, because the mean of its divisors is an integer number (10496509).

Almost surely, 2^20993017 is an apocalyptic number.

It is an amenable number.

20993017 is a deficient number, since it is larger than the sum of its proper divisors (1).

20993017 is an equidigital number, since it uses as much as digits as its factorization.

20993017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3402, while the sum is 31.

The square root of 20993017 is about 4581.8137238434. The cubic root of 20993017 is about 275.8618339820.

The spelling of 20993017 in words is "twenty million, nine hundred ninety-three thousand, seventeen".