1399978 has 8 divisors (see below), whose sum is σ = 2129760. Its totient is φ = 690060.

The previous prime is 1399963. The next prime is 1399999. The reversal of 1399978 is 8799931.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 4788 + ... + 5071.

It is an arithmetic number, because the mean of its divisors is an integer number (266220).

2^1399978 is an apocalyptic number.

1399978 is a deficient number, since it is larger than the sum of its proper divisors (729782).

1399978 is an equidigital number, since it uses as much as digits as its factorization.

1399978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9932.

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

The square root of 1399978 is about 1183.2066598866. The cubic root of 1399978 is about 111.8683082251.

The spelling of 1399978 in words is "one million, three hundred ninety-nine thousand, nine hundred seventy-eight".