20726813 has 2 divisors, whose sum is σ = 20726814. Its totient is φ = 20726812.

The previous prime is 20726807. The next prime is 20726819. The reversal of 20726813 is 31862702.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (20726807) and next prime (20726819).

It can be written as a sum of positive squares in only one way, i.e., 12124324 + 8602489 = 3482^2 + 2933^2 .

It is a cyclic number.

It is not a de Polignac number, because 20726813 - 2⁸ = 20726557 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20726819) 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, 10363406 + 10363407.

It is an arithmetic number, because the mean of its divisors is an integer number (10363407).

Almost surely, 2^20726813 is an apocalyptic number.

It is an amenable number.

20726813 is a deficient number, since it is larger than the sum of its proper divisors (1).

20726813 is an equidigital number, since it uses as much as digits as its factorization.

20726813 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 20726813 is about 4552.6709742743. The cubic root of 20726813 is about 274.6908393423.

The spelling of 20726813 in words is "twenty million, seven hundred twenty-six thousand, eight hundred thirteen".