21382572834 has 128 divisors (see below), whose sum is σ = 59354726400. Its totient is φ = 5564401920.

The previous prime is 21382572823. The next prime is 21382572859. The reversal of 21382572834 is 43827528312.

It is a self number, because there is not a number n which added to its sum of digits gives 21382572834.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 145537 + ... + 252875.

It is an arithmetic number, because the mean of its divisors is an integer number (463708800).

Almost surely, 2^21382572834 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21382572834, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29677363200).

21382572834 is an abundant number, since it is smaller than the sum of its proper divisors (37972153566).

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

21382572834 is a wasteful number, since it uses less digits than its factorization.

21382572834 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107405 (or 107399 counting only the distinct ones).

The product of its digits is 645120, while the sum is 45.

The spelling of 21382572834 in words is "twenty-one billion, three hundred eighty-two million, five hundred seventy-two thousand, eight hundred thirty-four".