21011111221012 has 48 divisors (see below), whose sum is σ = 40967753460480. Its totient is φ = 9346804841600.

The previous prime is 21011111220961. The next prime is 21011111221027. The reversal of 21011111221012 is 21012211111012.

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, 40000962 + ... + 40522822.

It is an arithmetic number, because the mean of its divisors is an integer number (853494863760).

Almost surely, 2^{21011111221012} is an apocalyptic number.

21011111221012 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21011111221012 is a deficient number, since it is larger than the sum of its proper divisors (19956642239468).

21011111221012 is a wasteful number, since it uses less digits than its factorization.

21011111221012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 541392 (or 541390 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 16.

Adding to 21011111221012 its reverse (21012211111012), we get a palindrome (42023322332024).

The spelling of 21011111221012 in words is "twenty-one trillion, eleven billion, one hundred eleven million, two hundred twenty-one thousand, twelve".