20705513 has 2 divisors, whose sum is σ = 20705514. Its totient is φ = 20705512.

The previous prime is 20705491. The next prime is 20705537. The reversal of 20705513 is 31550702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16875664 + 3829849 = 4108^2 + 1957^2 .

It is a cyclic number.

It is not a de Polignac number, because 20705513 - 2²⁰ = 19656937 is a prime.

It is not a weakly prime, because it can be changed into another prime (20705593) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10352756 + 10352757.

It is an arithmetic number, because the mean of its divisors is an integer number (10352757).

Almost surely, 2^20705513 is an apocalyptic number.

It is an amenable number.

20705513 is a deficient number, since it is larger than the sum of its proper divisors (1).

20705513 is an equidigital number, since it uses as much as digits as its factorization.

20705513 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1050, while the sum is 23.

The square root of 20705513 is about 4550.3310868551. The cubic root of 20705513 is about 274.5967113439.

The spelling of 20705513 in words is "twenty million, seven hundred five thousand, five hundred thirteen".