21112211121220 has 24 divisors (see below), whose sum is σ = 46669098268800. Its totient is φ = 8000416845792.

The previous prime is 21112211121167. The next prime is 21112211121227. The reversal of 21112211121220 is 2212111221112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is not an unprimeable number, because it can be changed into a prime (21112211121227) 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, 27779224780 + ... + 27779225539.

It is an arithmetic number, because the mean of its divisors is an integer number (1944545761200).

Almost surely, 2^{21112211121220} is an apocalyptic number.

21112211121220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21112211121220 is an abundant number, since it is smaller than the sum of its proper divisors (25556887147580).

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

21112211121220 is a wasteful number, since it uses less digits than its factorization.

21112211121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55558450347 (or 55558450345 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21112211121220 its reverse (2212111221112), we get a palindrome (23324322342332).

The spelling of 21112211121220 in words is "twenty-one trillion, one hundred twelve billion, two hundred eleven million, one hundred twenty-one thousand, two hundred twenty".