21212100121012 has 6 divisors (see below), whose sum is σ = 37121175211778. Its totient is φ = 10606050060504.

The previous prime is 21212100121007. The next prime is 21212100121013. The reversal of 21212100121012 is 21012100121212.

It can be written as a sum of positive squares in only one way, i.e., 21187572176016 + 24527944996 = 4602996^2 + 156614^2 .

It is a super-3 number, since 3×21212100121012³ (a number of 41 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212100121013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2651512515123 + ... + 2651512515130.

Almost surely, 2^{21212100121012} is an apocalyptic number.

It is an amenable number.

21212100121012 is a deficient number, since it is larger than the sum of its proper divisors (15909075090766).

21212100121012 is a wasteful number, since it uses less digits than its factorization.

21212100121012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5303025030257 (or 5303025030255 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21212100121012 its reverse (21012100121212), we get a palindrome (42224200242224).

The spelling of 21212100121012 in words is "twenty-one trillion, two hundred twelve billion, one hundred million, one hundred twenty-one thousand, twelve".