1978013 has 4 divisors (see below), whose sum is σ = 2015388. Its totient is φ = 1940640.

The previous prime is 1977991. The next prime is 1978021. The reversal of 1978013 is 3108791.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3108791 = 7 ⋅444113.

It can be written as a sum of positive squares in 2 ways, for example, as 1545049 + 432964 = 1243^2 + 658^2 .

It is a cyclic number.

It is not a de Polignac number, because 1978013 - 2⁸ = 1977757 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978063) 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, 18608 + ... + 18713.

It is an arithmetic number, because the mean of its divisors is an integer number (503847).

2^1978013 is an apocalyptic number.

It is an amenable number.

1978013 is a deficient number, since it is larger than the sum of its proper divisors (37375).

1978013 is an equidigital number, since it uses as much as digits as its factorization.

1978013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37374.

The product of its (nonzero) digits is 1512, while the sum is 29.

The square root of 1978013 is about 1406.4185010160. The cubic root of 1978013 is about 125.5287046186.

The spelling of 1978013 in words is "one million, nine hundred seventy-eight thousand, thirteen".