21783870780 has 96 divisors (see below), whose sum is σ = 70126027776. Its totient is φ = 4949339136.

The previous prime is 21783870769. The next prime is 21783870793. The reversal of 21783870780 is 8707838712.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 85149 + ... + 225428.

It is an arithmetic number, because the mean of its divisors is an integer number (730479456).

Almost surely, 2^21783870780 is an apocalyptic number.

21783870780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21783870780 is an abundant number, since it is smaller than the sum of its proper divisors (48342156996).

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

21783870780 is a wasteful number, since it uses less digits than its factorization.

21783870780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310763 (or 310761 counting only the distinct ones).

The product of its (nonzero) digits is 1053696, while the sum is 51.

The spelling of 21783870780 in words is "twenty-one billion, seven hundred eighty-three million, eight hundred seventy thousand, seven hundred eighty".