20390207 has 2 divisors, whose sum is σ = 20390208. Its totient is φ = 20390206.

The previous prime is 20390197. The next prime is 20390221. The reversal of 20390207 is 70209302.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20390207 - 2⁸ = 20389951 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 (20390297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10195103 + 10195104.

It is an arithmetic number, because the mean of its divisors is an integer number (10195104).

Almost surely, 2^20390207 is an apocalyptic number.

20390207 is a deficient number, since it is larger than the sum of its proper divisors (1).

20390207 is an equidigital number, since it uses as much as digits as its factorization.

20390207 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 756, while the sum is 23.

The square root of 20390207 is about 4515.5516827958. The cubic root of 20390207 is about 273.1957118359.

Adding to 20390207 its reverse (70209302), we get a palindrome (90599509).

The spelling of 20390207 in words is "twenty million, three hundred ninety thousand, two hundred seven".