1978847 has 4 divisors (see below), whose sum is σ = 2131080. Its totient is φ = 1826616.

The previous prime is 1978807. The next prime is 1978849. The reversal of 1978847 is 7488791.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7488791 = 67 ⋅111773.

It is a cyclic number.

It is not a de Polignac number, because 1978847 - 2⁸ = 1978591 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1978798 and 1978807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978849) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76097 + ... + 76122.

It is an arithmetic number, because the mean of its divisors is an integer number (532770).

2^1978847 is an apocalyptic number.

1978847 is a deficient number, since it is larger than the sum of its proper divisors (152233).

1978847 is a wasteful number, since it uses less digits than its factorization.

1978847 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152232.

The product of its digits is 112896, while the sum is 44.

The square root of 1978847 is about 1406.7149675752. The cubic root of 1978847 is about 125.5463445818.

The spelling of 1978847 in words is "one million, nine hundred seventy-eight thousand, eight hundred forty-seven".