21500442413220 has 96 divisors (see below), whose sum is σ = 63824951611008. Its totient is φ = 5389208430592.

The previous prime is 21500442413161. The next prime is 21500442413239. The reversal of 21500442413220 is 2231424400512.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12845994 + ... + 14422913.

It is an arithmetic number, because the mean of its divisors is an integer number (664843245948).

Almost surely, 2^{21500442413220} is an apocalyptic number.

21500442413220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21500442413220 is an abundant number, since it is smaller than the sum of its proper divisors (42324509197788).

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

21500442413220 is a wasteful number, since it uses less digits than its factorization.

21500442413220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27269709 (or 27269707 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 30.

Adding to 21500442413220 its reverse (2231424400512), we get a palindrome (23731866813732).

The spelling of 21500442413220 in words is "twenty-one trillion, five hundred billion, four hundred forty-two million, four hundred thirteen thousand, two hundred twenty".