21144423213 has 6 divisors (see below), whose sum is σ = 30541944654. Its totient is φ = 14096282136.

The previous prime is 21144423211. The next prime is 21144423257. The reversal of 21144423213 is 31232444112.

21144423213 is a `hidden beast` number, since 2 + 1 + 1 + 4 + 442 + 3 + 213 = 666.

It can be written as a sum of positive squares in only one way, i.e., 18555343524 + 2589079689 = 136218^2 + 50883^2 .

It is not a de Polignac number, because 21144423213 - 2¹ = 21144423211 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21144423211) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1174690170 + ... + 1174690187.

It is an arithmetic number, because the mean of its divisors is an integer number (5090324109).

Almost surely, 2^21144423213 is an apocalyptic number.

It is an amenable number.

21144423213 is a deficient number, since it is larger than the sum of its proper divisors (9397521441).

21144423213 is a wasteful number, since it uses less digits than its factorization.

21144423213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2349380363 (or 2349380360 counting only the distinct ones).

The product of its digits is 4608, while the sum is 27.

Adding to 21144423213 its reverse (31232444112), we get a palindrome (52376867325).

The spelling of 21144423213 in words is "twenty-one billion, one hundred forty-four million, four hundred twenty-three thousand, two hundred thirteen".