1978042859 has 4 divisors (see below), whose sum is σ = 2130200016. Its totient is φ = 1825885704.

The previous prime is 1978042831. The next prime is 1978042867. The reversal of 1978042859 is 9582408791.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9582408791 = 31 ⋅309109961.

It is a cyclic number.

It is not a de Polignac number, because 1978042859 - 2²⁴ = 1961265643 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 1978042859.

It is not an unprimeable number, because it can be changed into a prime (1978042879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76078559 + ... + 76078584.

It is an arithmetic number, because the mean of its divisors is an integer number (532550004).

Almost surely, 2^1978042859 is an apocalyptic number.

1978042859 is a deficient number, since it is larger than the sum of its proper divisors (152157157).

1978042859 is a wasteful number, since it uses less digits than its factorization.

1978042859 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152157156.

The product of its (nonzero) digits is 1451520, while the sum is 53.

The square root of 1978042859 is about 44475.1937488753. The cubic root of 1978042859 is about 1255.2933625293.

The spelling of 1978042859 in words is "one billion, nine hundred seventy-eight million, forty-two thousand, eight hundred fifty-nine".