20686613 has 2 divisors, whose sum is σ = 20686614. Its totient is φ = 20686612.

The previous prime is 20686607. The next prime is 20686619. The reversal of 20686613 is 31668602.

It is a balanced prime because it is at equal distance from previous prime (20686607) and next prime (20686619).

It can be written as a sum of positive squares in only one way, i.e., 20268004 + 418609 = 4502^2 + 647^2 .

It is a cyclic number.

It is not a de Polignac number, because 20686613 - 2⁴ = 20686597 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20686613.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20686619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10343306 + 10343307.

It is an arithmetic number, because the mean of its divisors is an integer number (10343307).

Almost surely, 2^20686613 is an apocalyptic number.

It is an amenable number.

20686613 is a deficient number, since it is larger than the sum of its proper divisors (1).

20686613 is an equidigital number, since it uses as much as digits as its factorization.

20686613 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 20686613 is about 4548.2538407613. The cubic root of 20686613 is about 274.5131352491.

The spelling of 20686613 in words is "twenty million, six hundred eighty-six thousand, six hundred thirteen".