21234307840 has 36 divisors (see below), whose sum is σ = 50862806064. Its totient is φ = 8493722624.

The previous prime is 21234307823. The next prime is 21234307873. The reversal of 21234307840 is 4870343212.

It is a junction number, because it is equal to n+sod(n) for n = 21234307796 and 21234307805.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8293372 + ... + 8295931.

It is an arithmetic number, because the mean of its divisors is an integer number (1412855724).

Almost surely, 2^21234307840 is an apocalyptic number.

21234307840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21234307840 is an abundant number, since it is smaller than the sum of its proper divisors (29628498224).

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

21234307840 is an equidigital number, since it uses as much as digits as its factorization.

21234307840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16589324 (or 16589310 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 34.

The spelling of 21234307840 in words is "twenty-one billion, two hundred thirty-four million, three hundred seven thousand, eight hundred forty".