21044042530 has 32 divisors (see below), whose sum is σ = 44346476160. Its totient is φ = 7039121280.

The previous prime is 21044042521. The next prime is 21044042543. The reversal of 21044042530 is 3524044012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21044042495 and 21044042504.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3663340 + ... + 3669079.

It is an arithmetic number, because the mean of its divisors is an integer number (1385827380).

Almost surely, 2^21044042530 is an apocalyptic number.

21044042530 is an abundant number, since it is smaller than the sum of its proper divisors (23302433630).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21044042530 is a wasteful number, since it uses less digits than its factorization.

21044042530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7332474.

The product of its (nonzero) digits is 3840, while the sum is 25.

Adding to 21044042530 its reverse (3524044012), we get a palindrome (24568086542).

The spelling of 21044042530 in words is "twenty-one billion, forty-four million, forty-two thousand, five hundred thirty".