21011221212212 has 24 divisors (see below), whose sum is σ = 45842664463680. Its totient is φ = 8186190082560.

The previous prime is 21011221212197. The next prime is 21011221212229. The reversal of 21011221212212 is 21221212211012.

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, 34109125037 + ... + 34109125652.

It is an arithmetic number, because the mean of its divisors is an integer number (1910111019320).

Almost surely, 2^{21011221212212} is an apocalyptic number.

21011221212212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21011221212212 is an abundant number, since it is smaller than the sum of its proper divisors (24831443251468).

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

21011221212212 is a wasteful number, since it uses less digits than its factorization.

21011221212212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68218250711 (or 68218250709 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 21011221212212 its reverse (21221212211012), we get a palindrome (42232433423224).

The spelling of 21011221212212 in words is "twenty-one trillion, eleven billion, two hundred twenty-one million, two hundred twelve thousand, two hundred twelve".