21234499860 has 144 divisors (see below), whose sum is σ = 69293314944. Its totient is φ = 4844512512.

The previous prime is 21234499849. The next prime is 21234499861. The reversal of 21234499860 is 6899443212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21234499861) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1631097 + ... + 1644063.

It is an arithmetic number, because the mean of its divisors is an integer number (481203576).

Almost surely, 2^21234499860 is an apocalyptic number.

21234499860 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21234499860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34646657472).

21234499860 is an abundant number, since it is smaller than the sum of its proper divisors (48058815084).

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

21234499860 is a wasteful number, since it uses less digits than its factorization.

21234499860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13550 (or 13541 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 48.

The spelling of 21234499860 in words is "twenty-one billion, two hundred thirty-four million, four hundred ninety-nine thousand, eight hundred sixty".