21044431342 has 32 divisors (see below), whose sum is σ = 36622782720. Its totient is φ = 8963268480.

The previous prime is 21044431339. The next prime is 21044431349. The reversal of 21044431342 is 24313444012.

It is a self number, because there is not a number n which added to its sum of digits gives 21044431342.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21044431349) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39042 + ... + 208837.

It is an arithmetic number, because the mean of its divisors is an integer number (1144461960).

Almost surely, 2^21044431342 is an apocalyptic number.

21044431342 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21044431342 is a deficient number, since it is larger than the sum of its proper divisors (15578351378).

21044431342 is a wasteful number, since it uses less digits than its factorization.

21044431342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248136.

The product of its (nonzero) digits is 9216, while the sum is 28.

Adding to 21044431342 its reverse (24313444012), we get a palindrome (45357875354).

The spelling of 21044431342 in words is "twenty-one billion, forty-four million, four hundred thirty-one thousand, three hundred forty-two".