1978747 has 4 divisors (see below), whose sum is σ = 2020896. Its totient is φ = 1936600.

The previous prime is 1978741. The next prime is 1978763. The reversal of 1978747 is 7478791.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1978747 - 2¹¹ = 1976699 is a prime.

It is a Duffinian number.

1978747 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21004 + ... + 21097.

It is an arithmetic number, because the mean of its divisors is an integer number (505224).

2^1978747 is an apocalyptic number.

1978747 is a deficient number, since it is larger than the sum of its proper divisors (42149).

1978747 is an equidigital number, since it uses as much as digits as its factorization.

1978747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42148.

The product of its digits is 98784, while the sum is 43.

The square root of 1978747 is about 1406.6794233229. The cubic root of 1978747 is about 125.5442297398.

The spelling of 1978747 in words is "one million, nine hundred seventy-eight thousand, seven hundred forty-seven".