21111212101210 has 192 divisors, whose sum is σ = 49007190675456. Its totient is φ = 6473493801600.

The previous prime is 21111212101193. The next prime is 21111212101249. The reversal of 21111212101210 is 1210121211112.

It is a super-3 number, since 3×21111212101210³ (a number of 41 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 178657167 + ... + 178775293.

It is an arithmetic number, because the mean of its divisors is an integer number (255245784768).

Almost surely, 2^{21111212101210} is an apocalyptic number.

21111212101210 is an abundant number, since it is smaller than the sum of its proper divisors (27895978574246).

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

21111212101210 is a wasteful number, since it uses less digits than its factorization.

21111212101210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118697 (or 118690 counting only the distinct ones).

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

Adding to 21111212101210 its reverse (1210121211112), we get a palindrome (22321333312322).

The spelling of 21111212101210 in words is "twenty-one trillion, one hundred eleven billion, two hundred twelve million, one hundred one thousand, two hundred ten".