1978849599 has 4 divisors (see below), whose sum is σ = 2638466136. Its totient is φ = 1319233064.

The previous prime is 1978849583. The next prime is 1978849619. The reversal of 1978849599 is 9959488791.

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 1978849599 - 2⁴ = 1978849583 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978849519) 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, 329808264 + ... + 329808269.

It is an arithmetic number, because the mean of its divisors is an integer number (659616534).

Almost surely, 2^1978849599 is an apocalyptic number.

1978849599 is a deficient number, since it is larger than the sum of its proper divisors (659616537).

1978849599 is an equidigital number, since it uses as much as digits as its factorization.

1978849599 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 659616536.

The product of its digits is 58786560, while the sum is 69.

The square root of 1978849599 is about 44484.2623744623. The cubic root of 1978849599 is about 1255.4639954554.

The spelling of 1978849599 in words is "one billion, nine hundred seventy-eight million, eight hundred forty-nine thousand, five hundred ninety-nine".