21353434220 has 12 divisors (see below), whose sum is σ = 44842211904. Its totient is φ = 8541373680.

The previous prime is 21353434217. The next prime is 21353434237. The reversal of 21353434220 is 2243435312.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 533835836 + ... + 533835875.

It is an arithmetic number, because the mean of its divisors is an integer number (3736850992).

Almost surely, 2^21353434220 is an apocalyptic number.

21353434220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21353434220 is an abundant number, since it is smaller than the sum of its proper divisors (23488777684).

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

21353434220 is a wasteful number, since it uses less digits than its factorization.

21353434220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1067671720 (or 1067671718 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 29.

Adding to 21353434220 its reverse (2243435312), we get a palindrome (23596869532).

The spelling of 21353434220 in words is "twenty-one billion, three hundred fifty-three million, four hundred thirty-four thousand, two hundred twenty".