21220313242 has 8 divisors (see below), whose sum is σ = 31838811732. Its totient is φ = 10607376000.

The previous prime is 21220313209. The next prime is 21220313321. The reversal of 21220313242 is 24231302212.

It can be written as a sum of positive squares in 2 ways, for example, as 16723403761 + 4496909481 = 129319^2 + 67059^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1380759 + ... + 1396042.

Almost surely, 2^21220313242 is an apocalyptic number.

21220313242 is a deficient number, since it is larger than the sum of its proper divisors (10618498490).

21220313242 is a wasteful number, since it uses less digits than its factorization.

21220313242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2780624.

The product of its (nonzero) digits is 1152, while the sum is 22.

Adding to 21220313242 its reverse (24231302212), we get a palindrome (45451615454).

The spelling of 21220313242 in words is "twenty-one billion, two hundred twenty million, three hundred thirteen thousand, two hundred forty-two".