21002011121220 has 48 divisors (see below), whose sum is σ = 61900664360640. Its totient is φ = 5305771230336.

The previous prime is 21002011121159. The next prime is 21002011121233. The reversal of 21002011121220 is 2212111020012.

It is a super-2 number, since 2×21002011121220² (a number of 27 digits) contains 22 as substring.

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 21002011121220.

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, 9211407247 + ... + 9211409526.

It is an arithmetic number, because the mean of its divisors is an integer number (1289597174180).

Almost surely, 2^{21002011121220} is an apocalyptic number.

21002011121220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21002011121220 is an abundant number, since it is smaller than the sum of its proper divisors (40898653239420).

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

21002011121220 is a wasteful number, since it uses less digits than its factorization.

21002011121220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18422816804 (or 18422816802 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21002011121220 its reverse (2212111020012), we get a palindrome (23214122141232).

The spelling of 21002011121220 in words is "twenty-one trillion, two billion, eleven million, one hundred twenty-one thousand, two hundred twenty".