21132123212 has 6 divisors (see below), whose sum is σ = 36981215628. Its totient is φ = 10566061604.

The previous prime is 21132123211. The next prime is 21132123223. The reversal of 21132123212 is 21232123112.

It is not an unprimeable number, because it can be changed into a prime (21132123211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2641515398 + ... + 2641515405.

It is an arithmetic number, because the mean of its divisors is an integer number (6163535938).

Almost surely, 2^21132123212 is an apocalyptic number.

It is an amenable number.

21132123212 is a deficient number, since it is larger than the sum of its proper divisors (15849092416).

21132123212 is a wasteful number, since it uses less digits than its factorization.

21132123212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5283030807 (or 5283030805 counting only the distinct ones).

The product of its digits is 288, while the sum is 20.

Adding to 21132123212 its reverse (21232123112), we get a palindrome (42364246324).

The spelling of 21132123212 in words is "twenty-one billion, one hundred thirty-two million, one hundred twenty-three thousand, two hundred twelve".