1978859839 has 4 divisors (see below), whose sum is σ = 2158756200. Its totient is φ = 1798963480.

The previous prime is 1978859833. The next prime is 1978859843. The reversal of 1978859839 is 9389588791.

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 1978859839 - 2⁹ = 1978859327 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978859833) 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, 89948164 + ... + 89948185.

It is an arithmetic number, because the mean of its divisors is an integer number (539689050).

Almost surely, 2^1978859839 is an apocalyptic number.

1978859839 is a deficient number, since it is larger than the sum of its proper divisors (179896361).

1978859839 is a wasteful number, since it uses less digits than its factorization.

1978859839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179896360.

The product of its digits is 39191040, while the sum is 67.

The square root of 1978859839 is about 44484.3774711977. The cubic root of 1978859839 is about 1255.4661610115.

The spelling of 1978859839 in words is "one billion, nine hundred seventy-eight million, eight hundred fifty-nine thousand, eight hundred thirty-nine".