21340204420 has 24 divisors (see below), whose sum is σ = 45573998400. Its totient is φ = 8391401952.

The previous prime is 21340204387. The next prime is 21340204481. The reversal of 21340204420 is 2440204312.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21340204391 and 21340204400.

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, 9041280 + ... + 9043639.

It is an arithmetic number, because the mean of its divisors is an integer number (1898916600).

Almost surely, 2^21340204420 is an apocalyptic number.

21340204420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21340204420 is an abundant number, since it is smaller than the sum of its proper divisors (24233793980).

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

21340204420 is a wasteful number, since it uses less digits than its factorization.

21340204420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18084987 (or 18084985 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 22.

Adding to 21340204420 its reverse (2440204312), we get a palindrome (23780408732).

The spelling of 21340204420 in words is "twenty-one billion, three hundred forty million, two hundred four thousand, four hundred twenty".