20606813 has 2 divisors, whose sum is σ = 20606814. Its totient is φ = 20606812.

The previous prime is 20606801. The next prime is 20606857. The reversal of 20606813 is 31860602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20313049 + 293764 = 4507^2 + 542^2 .

It is a cyclic number.

It is not a de Polignac number, because 20606813 - 2⁴ = 20606797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20606713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10303406 + 10303407.

It is an arithmetic number, because the mean of its divisors is an integer number (10303407).

Almost surely, 2^20606813 is an apocalyptic number.

It is an amenable number.

20606813 is a deficient number, since it is larger than the sum of its proper divisors (1).

20606813 is an equidigital number, since it uses as much as digits as its factorization.

20606813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 20606813 is about 4539.4727667429. The cubic root of 20606813 is about 274.1596960972.

The spelling of 20606813 in words is "twenty million, six hundred six thousand, eight hundred thirteen".