1809989261920 has 96 divisors (see below), whose sum is σ = 4948831641600. Its totient is φ = 612712429056.

The previous prime is 1809989261917. The next prime is 1809989261929. The reversal of 1809989261920 is 291629899081.

It is a super-2 number, since 2×1809989261920² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1809989261929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10139760 + ... + 10316719.

It is an arithmetic number, because the mean of its divisors is an integer number (51550329600).

Almost surely, 2^{1809989261920} is an apocalyptic number.

1809989261920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1809989261920 is an abundant number, since it is smaller than the sum of its proper divisors (3138842379680).

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

1809989261920 is a wasteful number, since it uses less digits than its factorization.

1809989261920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20456580 (or 20456572 counting only the distinct ones).

The product of its (nonzero) digits is 10077696, while the sum is 64.

The spelling of 1809989261920 in words is "one trillion, eight hundred nine billion, nine hundred eighty-nine million, two hundred sixty-one thousand, nine hundred twenty".