20669357 has 2 divisors, whose sum is σ = 20669358. Its totient is φ = 20669356.

The previous prime is 20669339. The next prime is 20669381. The reversal of 20669357 is 75396602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19945156 + 724201 = 4466^2 + 851^2 .

It is a cyclic number.

It is not a de Polignac number, because 20669357 - 2⁸ = 20669101 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 20669357.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20669317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10334678 + 10334679.

It is an arithmetic number, because the mean of its divisors is an integer number (10334679).

Almost surely, 2^20669357 is an apocalyptic number.

It is an amenable number.

20669357 is a deficient number, since it is larger than the sum of its proper divisors (1).

20669357 is an equidigital number, since it uses as much as digits as its factorization.

20669357 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 68040, while the sum is 38.

The square root of 20669357 is about 4546.3564532491. The cubic root of 20669357 is about 274.4367844804.

The spelling of 20669357 in words is "twenty million, six hundred sixty-nine thousand, three hundred fifty-seven".