20706213 has 16 divisors (see below), whose sum is σ = 30206016. Its totient is φ = 12512640.

The previous prime is 20706209. The next prime is 20706239. The reversal of 20706213 is 31260702.

It is a happy number.

It is not a de Polignac number, because 20706213 - 2² = 20706209 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20706213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20706293) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14395 + ... + 15767.

It is an arithmetic number, because the mean of its divisors is an integer number (1887876).

Almost surely, 2^20706213 is an apocalyptic number.

It is an amenable number.

20706213 is a deficient number, since it is larger than the sum of its proper divisors (9499803).

20706213 is a wasteful number, since it uses less digits than its factorization.

20706213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1844.

The product of its (nonzero) digits is 504, while the sum is 21.

The square root of 20706213 is about 4550.4080036849. The cubic root of 20706213 is about 274.5998057780.

Adding to 20706213 its reverse (31260702), we get a palindrome (51966915).

The spelling of 20706213 in words is "twenty million, seven hundred six thousand, two hundred thirteen".