20713289 has 2 divisors, whose sum is σ = 20713290. Its totient is φ = 20713288.

The previous prime is 20713261. The next prime is 20713291. The reversal of 20713289 is 98231702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16949689 + 3763600 = 4117^2 + 1940^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20713289 is a prime.

Together with 20713291, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20713219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10356644 + 10356645.

It is an arithmetic number, because the mean of its divisors is an integer number (10356645).

Almost surely, 2^20713289 is an apocalyptic number.

It is an amenable number.

20713289 is a deficient number, since it is larger than the sum of its proper divisors (1).

20713289 is an equidigital number, since it uses as much as digits as its factorization.

20713289 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 20713289 is about 4551.1854499680. The cubic root of 20713289 is about 274.6310821704.

The spelling of 20713289 in words is "twenty million, seven hundred thirteen thousand, two hundred eighty-nine".