21201212012213 has 16 divisors (see below), whose sum is σ = 21447445748736. Its totient is φ = 20956535414640.

The previous prime is 21201212012209. The next prime is 21201212012243. The reversal of 21201212012213 is 31221021210212.

It is a cyclic number.

It is not a de Polignac number, because 21201212012213 - 2² = 21201212012209 is a prime.

It is a super-2 number, since 2×21201212012213² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201212012243) 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, 48862820 + ... + 49294802.

It is an arithmetic number, because the mean of its divisors is an integer number (1340465359296).

Almost surely, 2^{21201212012213} is an apocalyptic number.

It is an amenable number.

21201212012213 is a deficient number, since it is larger than the sum of its proper divisors (246233736523).

21201212012213 is a wasteful number, since it uses less digits than its factorization.

21201212012213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433784.

The product of its (nonzero) digits is 192, while the sum is 20.

Adding to 21201212012213 its reverse (31221021210212), we get a palindrome (52422233222425).

The spelling of 21201212012213 in words is "twenty-one trillion, two hundred one billion, two hundred twelve million, twelve thousand, two hundred thirteen".