1378999 has 2 divisors, whose sum is σ = 1379000. Its totient is φ = 1378998.

The previous prime is 1378997. The next prime is 1379003. The reversal of 1378999 is 9998731.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1378999 - 2¹ = 1378997 is a prime.

Together with 1378997, it forms a pair of twin primes.

It is a plaindrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1378997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 689499 + 689500.

It is an arithmetic number, because the mean of its divisors is an integer number (689500).

2^1378999 is an apocalyptic number.

1378999 is a deficient number, since it is larger than the sum of its proper divisors (1).

1378999 is an equidigital number, since it uses as much as digits as its factorization.

1378999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 122472, while the sum is 46.

The square root of 1378999 is about 1174.3078812645. The cubic root of 1378999 is about 111.3067025679.

The spelling of 1378999 in words is "one million, three hundred seventy-eight thousand, nine hundred ninety-nine".