21404142244 has 24 divisors (see below), whose sum is σ = 38306441880. Its totient is φ = 10462040064.

The previous prime is 21404142223. The next prime is 21404142311. The reversal of 21404142244 is 44224140412.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 757900900 + 20646241344 = 27530^2 + 143688^2 .

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, 291349 + ... + 357340.

It is an arithmetic number, because the mean of its divisors is an integer number (1596101745).

Almost surely, 2^21404142244 is an apocalyptic number.

It is an amenable number.

21404142244 is a deficient number, since it is larger than the sum of its proper divisors (16902299636).

21404142244 is a wasteful number, since it uses less digits than its factorization.

21404142244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 648879 (or 648877 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 28.

Adding to 21404142244 its reverse (44224140412), we get a palindrome (65628282656).

The spelling of 21404142244 in words is "twenty-one billion, four hundred four million, one hundred forty-two thousand, two hundred forty-four".