2138989 has 2 divisors, whose sum is σ = 2138990. Its totient is φ = 2138988.

The previous prime is 2138987. The next prime is 2138999. The reversal of 2138989 is 9898312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2125764 + 13225 = 1458^2 + 115^2 .

It is a cyclic number.

It is not a de Polignac number, because 2138989 - 2¹ = 2138987 is a prime.

Together with 2138987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2138987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1069494 + 1069495.

It is an arithmetic number, because the mean of its divisors is an integer number (1069495).

2^2138989 is an apocalyptic number.

It is an amenable number.

2138989 is a deficient number, since it is larger than the sum of its proper divisors (1).

2138989 is an equidigital number, since it uses as much as digits as its factorization.

2138989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 40.

The square root of 2138989 is about 1462.5282903247. The cubic root of 2138989 is about 128.8455776933.

The spelling of 2138989 in words is "two million, one hundred thirty-eight thousand, nine hundred eighty-nine".