1998765878 has 8 divisors (see below), whose sum is σ = 3021756672. Its totient is φ = 991513656.

The previous prime is 1998765841. The next prime is 1998765893. The reversal of 1998765878 is 8785678991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×1998765878² = 7990130070114221768, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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, 3934325 + ... + 3934832.

It is an arithmetic number, because the mean of its divisors is an integer number (377719584).

Almost surely, 2^1998765878 is an apocalyptic number.

1998765878 is a deficient number, since it is larger than the sum of its proper divisors (1022990794).

1998765878 is a wasteful number, since it uses less digits than its factorization.

1998765878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7869286.

The product of its digits is 60963840, while the sum is 68.

The square root of 1998765878 is about 44707.5595173792. The cubic root of 1998765878 is about 1259.6618471919.

The spelling of 1998765878 in words is "one billion, nine hundred ninety-eight million, seven hundred sixty-five thousand, eight hundred seventy-eight".