819988642 has 32 divisors (see below), whose sum is σ = 1424983104. Its totient is φ = 349747200.

The previous prime is 819988621. The next prime is 819988651. The reversal of 819988642 is 246889918.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 128917 + ... + 135127.

It is an arithmetic number, because the mean of its divisors is an integer number (44530722).

Almost surely, 2^819988642 is an apocalyptic number.

819988642 is a deficient number, since it is larger than the sum of its proper divisors (604994462).

819988642 is a wasteful number, since it uses less digits than its factorization.

819988642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6594.

The product of its digits is 1990656, while the sum is 55.

The square root of 819988642 is about 28635.4438065835. The cubic root of 819988642 is about 935.9858407591.

The spelling of 819988642 in words is "eight hundred nineteen million, nine hundred eighty-eight thousand, six hundred forty-two".