21783189816 has 64 divisors (see below), whose sum is σ = 60858727200. Its totient is φ = 7219079424.

The previous prime is 21783189811. The next prime is 21783189823. The reversal of 21783189816 is 61898138712.

It is a super-2 number, since 2×21783189816² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21783189811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 254101 + ... + 328836.

Almost surely, 2^21783189816 is an apocalyptic number.

It is an amenable number.

21783189816 is an abundant number, since it is smaller than the sum of its proper divisors (39075537384).

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

21783189816 is a wasteful number, since it uses less digits than its factorization.

21783189816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 583125 (or 583115 counting only the distinct ones).

The product of its digits is 1161216, while the sum is 54.

The spelling of 21783189816 in words is "twenty-one billion, seven hundred eighty-three million, one hundred eighty-nine thousand, eight hundred sixteen".