20935813 has 2 divisors, whose sum is σ = 20935814. Its totient is φ = 20935812.

The previous prime is 20935799. The next prime is 20935829. The reversal of 20935813 is 31853902.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17164449 + 3771364 = 4143^2 + 1942^2 .

It is a cyclic number.

It is not a de Polignac number, because 20935813 - 2¹⁷ = 20804741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20935843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10467906 + 10467907.

It is an arithmetic number, because the mean of its divisors is an integer number (10467907).

Almost surely, 2^20935813 is an apocalyptic number.

It is an amenable number.

20935813 is a deficient number, since it is larger than the sum of its proper divisors (1).

20935813 is an equidigital number, since it uses as much as digits as its factorization.

20935813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 20935813 is about 4575.5669594051. The cubic root of 20935813 is about 275.6110401830.

The spelling of 20935813 in words is "twenty million, nine hundred thirty-five thousand, eight hundred thirteen".