21011221120220 has 24 divisors (see below), whose sum is σ = 44154355455504. Its totient is φ = 8398623476096.

The previous prime is 21011221120217. The next prime is 21011221120223. The reversal of 21011221120220 is 2202112211012.

It is an interprime number because it is at equal distance from previous prime (21011221120217) and next prime (21011221120223).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011221120223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 366531374 + ... + 366588693.

It is an arithmetic number, because the mean of its divisors is an integer number (1839764810646).

Almost surely, 2^{21011221120220} is an apocalyptic number.

21011221120220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21011221120220 is an abundant number, since it is smaller than the sum of its proper divisors (23143134335284).

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

21011221120220 is a wasteful number, since it uses less digits than its factorization.

21011221120220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 733121509 (or 733121507 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21011221120220 its reverse (2202112211012), we get a palindrome (23213333331232).

The spelling of 21011221120220 in words is "twenty-one trillion, eleven billion, two hundred twenty-one million, one hundred twenty thousand, two hundred twenty".