20813953 has 2 divisors, whose sum is σ = 20813954. Its totient is φ = 20813952.

The previous prime is 20813929. The next prime is 20813957. The reversal of 20813953 is 35931802.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17740944 + 3073009 = 4212^2 + 1753^2 .

It is a cyclic number.

It is not a de Polignac number, because 20813953 - 2⁵ = 20813921 is a prime.

It is not a weakly prime, because it can be changed into another prime (20813957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10406976 + 10406977.

It is an arithmetic number, because the mean of its divisors is an integer number (10406977).

Almost surely, 2^20813953 is an apocalyptic number.

It is an amenable number.

20813953 is a deficient number, since it is larger than the sum of its proper divisors (1).

20813953 is an equidigital number, since it uses as much as digits as its factorization.

20813953 is an odious number, because the sum of its binary digits is odd.

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

The square root of 20813953 is about 4562.2311427634. The cubic root of 20813953 is about 275.0752543357.

It can be divided in two parts, 208 and 13953, that added together give a square (14161 = 119²).

The spelling of 20813953 in words is "twenty million, eight hundred thirteen thousand, nine hundred fifty-three".