20702993 has 2 divisors, whose sum is σ = 20702994. Its totient is φ = 20702992.

The previous prime is 20702987. The next prime is 20703031. The reversal of 20702993 is 39920702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14190289 + 6512704 = 3767^2 + 2552^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20702993 is a prime.

It is a super-2 number, since 2×20702993² = 857227838316098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20702293) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10351496 + 10351497.

It is an arithmetic number, because the mean of its divisors is an integer number (10351497).

Almost surely, 2^20702993 is an apocalyptic number.

It is an amenable number.

20702993 is a deficient number, since it is larger than the sum of its proper divisors (1).

20702993 is an equidigital number, since it uses as much as digits as its factorization.

20702993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6804, while the sum is 32.

The square root of 20702993 is about 4550.0541755017. The cubic root of 20702993 is about 274.5855708039.

The spelling of 20702993 in words is "twenty million, seven hundred two thousand, nine hundred ninety-three".