21213604016220 has 192 divisors, whose sum is σ = 74746865442816. Its totient is φ = 4366825048320.

The previous prime is 21213604016201. The next prime is 21213604016239. The reversal of 21213604016220 is 2261040631212.

It is an interprime number because it is at equal distance from previous prime (21213604016201) and next prime (21213604016239).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 20962152 + ... + 21950831.

It is an arithmetic number, because the mean of its divisors is an integer number (389306590848).

Almost surely, 2^{21213604016220} is an apocalyptic number.

21213604016220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21213604016220 is an abundant number, since it is smaller than the sum of its proper divisors (53533261426596).

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

21213604016220 is a wasteful number, since it uses less digits than its factorization.

21213604016220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42913120 (or 42913118 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 30.

Adding to 21213604016220 its reverse (2261040631212), we get a palindrome (23474644647432).

The spelling of 21213604016220 in words is "twenty-one trillion, two hundred thirteen billion, six hundred four million, sixteen thousand, two hundred twenty".