1978259 has 4 divisors (see below), whose sum is σ = 1988400. Its totient is φ = 1968120.

The previous prime is 1978219. The next prime is 1978267. The reversal of 1978259 is 9528791.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9528791 = 29 ⋅328579.

It is a cyclic number.

It is not a de Polignac number, because 1978259 - 2¹² = 1974163 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1978219) 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, 4772 + ... + 5169.

It is an arithmetic number, because the mean of its divisors is an integer number (497100).

2^1978259 is an apocalyptic number.

1978259 is a deficient number, since it is larger than the sum of its proper divisors (10141).

1978259 is an equidigital number, since it uses as much as digits as its factorization.

1978259 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10140.

The product of its digits is 45360, while the sum is 41.

The square root of 1978259 is about 1406.5059544844. The cubic root of 1978259 is about 125.5339082887.

The spelling of 1978259 in words is "one million, nine hundred seventy-eight thousand, two hundred fifty-nine".