1989669891 has 16 divisors (see below), whose sum is σ = 2896548480. Its totient is φ = 1204825920.

The previous prime is 1989669881. The next prime is 1989669907.

1989669891 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1989669891 - 2¹⁷ = 1989538819 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1989669841) by changing a digit.

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, 14100 + ... + 64638.

It is an arithmetic number, because the mean of its divisors is an integer number (181034280).

Almost surely, 2^1989669891 is an apocalyptic number.

1989669891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1989669891 is a deficient number, since it is larger than the sum of its proper divisors (906878589).

1989669891 is a wasteful number, since it uses less digits than its factorization.

1989669891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51746.

The product of its digits is 15116544, while the sum is 66.

The square root of 1989669891 is about 44605.7159005435. The cubic root of 1989669891 is about 1257.7481175222.

The spelling of 1989669891 in words is "one billion, nine hundred eighty-nine million, six hundred sixty-nine thousand, eight hundred ninety-one".