21810467680 has 24 divisors (see below), whose sum is σ = 51527230272. Its totient is φ = 8724187008.

The previous prime is 21810467659. The next prime is 21810467687. The reversal of 21810467680 is 8676401812.

It is a Smith number, since the sum of its digits (43) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21810467687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68157552 + ... + 68157871.

It is an arithmetic number, because the mean of its divisors is an integer number (2146967928).

Almost surely, 2^21810467680 is an apocalyptic number.

21810467680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21810467680 is an abundant number, since it is smaller than the sum of its proper divisors (29716762592).

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

21810467680 is a wasteful number, since it uses less digits than its factorization.

21810467680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136315438 (or 136315430 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 43.

The spelling of 21810467680 in words is "twenty-one billion, eight hundred ten million, four hundred sixty-seven thousand, six hundred eighty".