1978517904 has 80 divisors (see below), whose sum is σ = 5625336384. Its totient is φ = 594227200.

The previous prime is 1978517873. The next prime is 1978517911. The reversal of 1978517904 is 4097158791.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43084 + ... + 76244.

Almost surely, 2^1978517904 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1978517904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2812668192).

1978517904 is an abundant number, since it is smaller than the sum of its proper divisors (3646818480).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1978517904 is a wasteful number, since it uses less digits than its factorization.

1978517904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33296 (or 33290 counting only the distinct ones).

The product of its (nonzero) digits is 635040, while the sum is 51.

The square root of 1978517904 is about 44480.5339896004. The cubic root of 1978517904 is about 1255.3938445287.

The spelling of 1978517904 in words is "one billion, nine hundred seventy-eight million, five hundred seventeen thousand, nine hundred four".