1989687920 has 40 divisors (see below), whose sum is σ = 5046574320. Its totient is φ = 723522560.

The previous prime is 1989687919. The next prime is 1989687943. The reversal of 1989687920 is 297869891.

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 1989687920.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1129625 + ... + 1131384.

It is an arithmetic number, because the mean of its divisors is an integer number (126164358).

Almost surely, 2^1989687920 is an apocalyptic number.

1989687920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1989687920 is an abundant number, since it is smaller than the sum of its proper divisors (3056886400).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1989687920 is a wasteful number, since it uses less digits than its factorization.

1989687920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2261033 (or 2261027 counting only the distinct ones).

The product of its (nonzero) digits is 3919104, while the sum is 59.

The square root of 1989687920 is about 44605.9179930197. The cubic root of 1989687920 is about 1257.7519164560.

The spelling of 1989687920 in words is "one billion, nine hundred eighty-nine million, six hundred eighty-seven thousand, nine hundred twenty".