21404421242 has 4 divisors (see below), whose sum is σ = 32106631866. Its totient is φ = 10702210620.

The previous prime is 21404421223. The next prime is 21404421271. The reversal of 21404421242 is 24212440412.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 13513830001 + 7890591241 = 116249^2 + 88829^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5351105309 + ... + 5351105312.

Almost surely, 2^21404421242 is an apocalyptic number.

21404421242 is a deficient number, since it is larger than the sum of its proper divisors (10702210624).

21404421242 is a wasteful number, since it uses less digits than its factorization.

21404421242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10702210623.

The product of its (nonzero) digits is 4096, while the sum is 26.

Adding to 21404421242 its reverse (24212440412), we get a palindrome (45616861654).

The spelling of 21404421242 in words is "twenty-one billion, four hundred four million, four hundred twenty-one thousand, two hundred forty-two".