21131243044 has 12 divisors (see below), whose sum is σ = 37003652224. Its totient is φ = 10558770984.

The previous prime is 21131243041. The next prime is 21131243113. The reversal of 21131243044 is 44034213112.

It is not an unprimeable number, because it can be changed into a prime (21131243041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1705692 + ... + 1718035.

Almost surely, 2^21131243044 is an apocalyptic number.

It is an amenable number.

21131243044 is a deficient number, since it is larger than the sum of its proper divisors (15872409180).

21131243044 is a wasteful number, since it uses less digits than its factorization.

21131243044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3425274 (or 3425272 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 25.

Adding to 21131243044 its reverse (44034213112), we get a palindrome (65165456156).

The spelling of 21131243044 in words is "twenty-one billion, one hundred thirty-one million, two hundred forty-three thousand, forty-four".