20378489 has 2 divisors, whose sum is σ = 20378490. Its totient is φ = 20378488.

The previous prime is 20378473. The next prime is 20378497. The reversal of 20378489 is 98487302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17572864 + 2805625 = 4192^2 + 1675^2 .

It is a cyclic number.

It is not a de Polignac number, because 20378489 - 2⁴ = 20378473 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20378429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10189244 + 10189245.

It is an arithmetic number, because the mean of its divisors is an integer number (10189245).

Almost surely, 2^20378489 is an apocalyptic number.

It is an amenable number.

20378489 is a deficient number, since it is larger than the sum of its proper divisors (1).

20378489 is an equidigital number, since it uses as much as digits as its factorization.

20378489 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96768, while the sum is 41.

The square root of 20378489 is about 4514.2539804490. The cubic root of 20378489 is about 273.1433677409.

The spelling of 20378489 in words is "twenty million, three hundred seventy-eight thousand, four hundred eighty-nine".