21084829830 has 24 divisors (see below), whose sum is σ = 54820557792. Its totient is φ = 5622621264.

The previous prime is 21084829811. The next prime is 21084829837. The reversal of 21084829830 is 3892848012.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21084829837) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 117137854 + ... + 117138033.

It is an arithmetic number, because the mean of its divisors is an integer number (2284189908).

Almost surely, 2^21084829830 is an apocalyptic number.

21084829830 is an abundant number, since it is smaller than the sum of its proper divisors (33735727962).

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

21084829830 is a wasteful number, since it uses less digits than its factorization.

21084829830 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234275900 (or 234275897 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 45.

The spelling of 21084829830 in words is "twenty-one billion, eighty-four million, eight hundred twenty-nine thousand, eight hundred thirty".