1988219865 has 16 divisors (see below), whose sum is σ = 3181704768. Its totient is φ = 1060199616.

The previous prime is 1988219851. The next prime is 1988219951. The reversal of 1988219865 is 5689128891.

It is not a de Polignac number, because 1988219865 - 2¹⁷ = 1988088793 is a prime.

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, 160794 + ... + 172716.

It is an arithmetic number, because the mean of its divisors is an integer number (198856548).

Almost surely, 2^1988219865 is an apocalyptic number.

1988219865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1988219865 is a deficient number, since it is larger than the sum of its proper divisors (1193484903).

1988219865 is a wasteful number, since it uses less digits than its factorization.

1988219865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23048.

The product of its digits is 2488320, while the sum is 57.

The square root of 1988219865 is about 44589.4591243267. The cubic root of 1988219865 is about 1257.4425038960.

The spelling of 1988219865 in words is "one billion, nine hundred eighty-eight million, two hundred nineteen thousand, eight hundred sixty-five".