20389913 has 2 divisors, whose sum is σ = 20389914. Its totient is φ = 20389912.

The previous prime is 20389903. The next prime is 20389927. The reversal of 20389913 is 31998302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13191424 + 7198489 = 3632^2 + 2683^2 .

It is a cyclic number.

It is not a de Polignac number, because 20389913 - 2⁸ = 20389657 is a prime.

It is not a weakly prime, because it can be changed into another prime (20389903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10194956 + 10194957.

It is an arithmetic number, because the mean of its divisors is an integer number (10194957).

Almost surely, 2^20389913 is an apocalyptic number.

It is an amenable number.

20389913 is a deficient number, since it is larger than the sum of its proper divisors (1).

20389913 is an equidigital number, since it uses as much as digits as its factorization.

20389913 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 20389913 is about 4515.5191285167. The cubic root of 20389913 is about 273.1943987885.

The spelling of 20389913 in words is "twenty million, three hundred eighty-nine thousand, nine hundred thirteen".