21606424340 has 24 divisors (see below), whose sum is σ = 45414673920. Its totient is φ = 8634725408.

The previous prime is 21606424337. The next prime is 21606424387. The reversal of 21606424340 is 4342460612.

It is a junction number, because it is equal to n+sod(n) for n = 21606424297 and 21606424306.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 467660 + ... + 511779.

It is an arithmetic number, because the mean of its divisors is an integer number (1892278080).

Almost surely, 2^21606424340 is an apocalyptic number.

21606424340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21606424340 is an abundant number, since it is smaller than the sum of its proper divisors (23808249580).

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

21606424340 is a wasteful number, since it uses less digits than its factorization.

21606424340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 980551 (or 980549 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 32.

Adding to 21606424340 its reverse (4342460612), we get a palindrome (25948884952).

The spelling of 21606424340 in words is "twenty-one billion, six hundred six million, four hundred twenty-four thousand, three hundred forty".