21144455212 has 24 divisors (see below), whose sum is σ = 37085756400. Its totient is φ = 10548550656.

The previous prime is 21144455153. The next prime is 21144455257. The reversal of 21144455212 is 21255444112.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5989864 + ... + 5993392.

It is an arithmetic number, because the mean of its divisors is an integer number (1545239850).

Almost surely, 2^21144455212 is an apocalyptic number.

It is an amenable number.

21144455212 is a deficient number, since it is larger than the sum of its proper divisors (15941301188).

21144455212 is a wasteful number, since it uses less digits than its factorization.

21144455212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6465 (or 6463 counting only the distinct ones).

The product of its digits is 12800, while the sum is 31.

Adding to 21144455212 its reverse (21255444112), we get a palindrome (42399899324).

The spelling of 21144455212 in words is "twenty-one billion, one hundred forty-four million, four hundred fifty-five thousand, two hundred twelve".