20667389 has 2 divisors, whose sum is σ = 20667390. Its totient is φ = 20667388.

The previous prime is 20667377. The next prime is 20667397. The reversal of 20667389 is 98376602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13468900 + 7198489 = 3670^2 + 2683^2 .

It is a cyclic number.

It is not a de Polignac number, because 20667389 - 2⁴ = 20667373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20667589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10333694 + 10333695.

It is an arithmetic number, because the mean of its divisors is an integer number (10333695).

Almost surely, 2^20667389 is an apocalyptic number.

It is an amenable number.

20667389 is a deficient number, since it is larger than the sum of its proper divisors (1).

20667389 is an equidigital number, since it uses as much as digits as its factorization.

20667389 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108864, while the sum is 41.

The square root of 20667389 is about 4546.1400110423. The cubic root of 20667389 is about 274.4280741831.

The spelling of 20667389 in words is "twenty million, six hundred sixty-seven thousand, three hundred eighty-nine".