1397978 has 8 divisors (see below), whose sum is σ = 2220372. Its totient is φ = 657856.

The previous prime is 1397959. The next prime is 1397983. The reversal of 1397978 is 8797931.

It can be written as a sum of positive squares in 2 ways, for example, as 1315609 + 82369 = 1147^2 + 287^2 .

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, 20525 + ... + 20592.

2^1397978 is an apocalyptic number.

1397978 is a deficient number, since it is larger than the sum of its proper divisors (822394).

1397978 is a wasteful number, since it uses less digits than its factorization.

1397978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41136.

The product of its digits is 95256, while the sum is 44.

The square root of 1397978 is about 1182.3611969276. The cubic root of 1397978 is about 111.8150113771.

The spelling of 1397978 in words is "one million, three hundred ninety-seven thousand, nine hundred seventy-eight".