21553351220212 has 48 divisors (see below), whose sum is σ = 43636928775552. Its totient is φ = 9123586047360.

The previous prime is 21553351220201. The next prime is 21553351220249. The reversal of 21553351220212 is 21202215335512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8191578 + ... + 10498030.

It is an arithmetic number, because the mean of its divisors is an integer number (909102682824).

Almost surely, 2^{21553351220212} is an apocalyptic number.

It is an amenable number.

21553351220212 is an abundant number, since it is smaller than the sum of its proper divisors (22083577555340).

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

21553351220212 is a wasteful number, since it uses less digits than its factorization.

21553351220212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2310568 (or 2310566 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 34.

Adding to 21553351220212 its reverse (21202215335512), we get a palindrome (42755566555724).

The spelling of 21553351220212 in words is "twenty-one trillion, five hundred fifty-three billion, three hundred fifty-one million, two hundred twenty thousand, two hundred twelve".