1989764991 has 12 divisors (see below), whose sum is σ = 2874521832. Its totient is φ = 1326317616.

The previous prime is 1989764963. The next prime is 1989764993. The reversal of 1989764991 is 1994679891.

It is not a de Polignac number, because 1989764991 - 2⁹ = 1989764479 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1989764993) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 79320 + ... + 101346.

It is an arithmetic number, because the mean of its divisors is an integer number (239543486).

Almost surely, 2^1989764991 is an apocalyptic number.

1989764991 is a deficient number, since it is larger than the sum of its proper divisors (884756841).

1989764991 is a wasteful number, since it uses less digits than its factorization.

1989764991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32070 (or 32067 counting only the distinct ones).

The product of its digits is 8817984, while the sum is 63.

The square root of 1989764991 is about 44606.7818946850. The cubic root of 1989764991 is about 1257.7681560122.

The spelling of 1989764991 in words is "one billion, nine hundred eighty-nine million, seven hundred sixty-four thousand, nine hundred ninety-one".