21211705716212 has 48 divisors (see below), whose sum is σ = 41187172723200. Its totient is φ = 9476944702560.

The previous prime is 21211705716203. The next prime is 21211705716217. The reversal of 21211705716212 is 21261750711212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211705716217) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18174593 + ... + 19306455.

It is an arithmetic number, because the mean of its divisors is an integer number (858066098400).

Almost surely, 2^{21211705716212} is an apocalyptic number.

21211705716212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21211705716212 is a deficient number, since it is larger than the sum of its proper divisors (19975467006988).

21211705716212 is a wasteful number, since it uses less digits than its factorization.

21211705716212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1139156 (or 1139154 counting only the distinct ones).

The product of its (nonzero) digits is 23520, while the sum is 38.

The spelling of 21211705716212 in words is "twenty-one trillion, two hundred eleven billion, seven hundred five million, seven hundred sixteen thousand, two hundred twelve".