21244304042 has 8 divisors (see below), whose sum is σ = 34317721956. Its totient is φ = 9805063392.

The previous prime is 21244304041. The next prime is 21244304051. The reversal of 21244304042 is 24040344212.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 16427805241 + 4816498801 = 128171^2 + 69401^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Harshad number since it is a multiple of its sum of digits (26), and also a Moran number because the ratio is a prime number: 817088617 = 21244304042 / (2 + 1 + 2 + 4 + 4 + 3 + 0 + 4 + 0 + 4 + 2).

It is not an unprimeable number, because it can be changed into a prime (21244304041) 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, 408544283 + ... + 408544334.

Almost surely, 2^21244304042 is an apocalyptic number.

21244304042 is a deficient number, since it is larger than the sum of its proper divisors (13073417914).

21244304042 is a wasteful number, since it uses less digits than its factorization.

21244304042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 817088632.

The product of its (nonzero) digits is 6144, while the sum is 26.

Adding to 21244304042 its reverse (24040344212), we get a palindrome (45284648254).

The spelling of 21244304042 in words is "twenty-one billion, two hundred forty-four million, three hundred four thousand, forty-two".