21234140040 has 64 divisors (see below), whose sum is σ = 66472099200. Its totient is φ = 5416243712.

The previous prime is 21234140033. The next prime is 21234140069. The reversal of 21234140040 is 4004143212.

It is a junction number, because it is equal to n+sod(n) for n = 21234139989 and 21234140016.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3844005 + ... + 3849524.

It is an arithmetic number, because the mean of its divisors is an integer number (1038626550).

Almost surely, 2^21234140040 is an apocalyptic number.

21234140040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21234140040 is an abundant number, since it is smaller than the sum of its proper divisors (45237959160).

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

21234140040 is a wasteful number, since it uses less digits than its factorization.

21234140040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7693566 (or 7693562 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21234140040 its reverse (4004143212), we get a palindrome (25238283252).

The spelling of 21234140040 in words is "twenty-one billion, two hundred thirty-four million, one hundred forty thousand, forty".