21101031011220 has 24 divisors (see below), whose sum is σ = 59082886831584. Its totient is φ = 5626941602976.

The previous prime is 21101031011197. The next prime is 21101031011293. The reversal of 21101031011220 is 2211013010112.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21101031011220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 175841925034 + ... + 175841925153.

It is an arithmetic number, because the mean of its divisors is an integer number (2461786951316).

Almost surely, 2^{21101031011220} is an apocalyptic number.

21101031011220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21101031011220 is an abundant number, since it is smaller than the sum of its proper divisors (37981855820364).

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

21101031011220 is a wasteful number, since it uses less digits than its factorization.

21101031011220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351683850199 (or 351683850197 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 21101031011220 its reverse (2211013010112), we get a palindrome (23312044021332).

The spelling of 21101031011220 in words is "twenty-one trillion, one hundred one billion, thirty-one million, eleven thousand, two hundred twenty".