1989815788 has 12 divisors (see below), whose sum is σ = 3505239472. Its totient is φ = 988318800.

The previous prime is 1989815783. The next prime is 1989815797. The reversal of 1989815788 is 8875189891.

It is a super-3 number, since 3×1989815788³ (a number of 29 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1989815783) 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, 1646595 + ... + 1647802.

Almost surely, 2^1989815788 is an apocalyptic number.

It is an amenable number.

1989815788 is a deficient number, since it is larger than the sum of its proper divisors (1515423684).

1989815788 is a wasteful number, since it uses less digits than its factorization.

1989815788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3294552 (or 3294550 counting only the distinct ones).

The product of its digits is 11612160, while the sum is 64.

The square root of 1989815788 is about 44607.3512775641. The cubic root of 1989815788 is about 1257.7788591699.

The spelling of 1989815788 in words is "one billion, nine hundred eighty-nine million, eight hundred fifteen thousand, seven hundred eighty-eight".