21000011011220 has 48 divisors (see below), whose sum is σ = 44173706451840. Its totient is φ = 8385970993536.

The previous prime is 21000011011163. The next prime is 21000011011237. The reversal of 21000011011220 is 2211011000012.

It is a super-2 number, since 2×21000011011220² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 303683969 + ... + 303753111.

It is an arithmetic number, because the mean of its divisors is an integer number (920285551080).

Almost surely, 2^{21000011011220} is an apocalyptic number.

21000011011220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000011011220 is an abundant number, since it is smaller than the sum of its proper divisors (23173695440620).

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

21000011011220 is a wasteful number, since it uses less digits than its factorization.

21000011011220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94304 (or 94302 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21000011011220 its reverse (2211011000012), we get a palindrome (23211022011232).

The spelling of 21000011011220 in words is "twenty-one trillion, eleven million, eleven thousand, two hundred twenty".