20669513 has 2 divisors, whose sum is σ = 20669514. Its totient is φ = 20669512.

The previous prime is 20669497. The next prime is 20669527. The reversal of 20669513 is 31596602.

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., 16540489 + 4129024 = 4067^2 + 2032^2 .

It is a cyclic number.

It is not a de Polignac number, because 20669513 - 2⁴ = 20669497 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20669513.

It is not a weakly prime, because it can be changed into another prime (20669543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10334756 + 10334757.

It is an arithmetic number, because the mean of its divisors is an integer number (10334757).

Almost surely, 2^20669513 is an apocalyptic number.

It is an amenable number.

20669513 is a deficient number, since it is larger than the sum of its proper divisors (1).

20669513 is an equidigital number, since it uses as much as digits as its factorization.

20669513 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9720, while the sum is 32.

The square root of 20669513 is about 4546.3736098126. The cubic root of 20669513 is about 274.4374749071.

The spelling of 20669513 in words is "twenty million, six hundred sixty-nine thousand, five hundred thirteen".