1978897 has 8 divisors (see below), whose sum is σ = 2088576. Its totient is φ = 1871232.

The previous prime is 1978891. The next prime is 1978909. The reversal of 1978897 is 7988791.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1978897 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1978897.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978891) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1788 + ... + 2674.

It is an arithmetic number, because the mean of its divisors is an integer number (261072).

2^1978897 is an apocalyptic number.

It is an amenable number.

1978897 is a deficient number, since it is larger than the sum of its proper divisors (109679).

1978897 is an equidigital number, since it uses as much as digits as its factorization.

1978897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1007.

The product of its digits is 254016, while the sum is 49.

The square root of 1978897 is about 1406.7327393645. The cubic root of 1978897 is about 125.5474019760.

The spelling of 1978897 in words is "one million, nine hundred seventy-eight thousand, eight hundred ninety-seven".