21022424404 has 12 divisors (see below), whose sum is σ = 36794992500. Its totient is φ = 10509569408.

The previous prime is 21022424387. The next prime is 21022424459. The reversal of 21022424404 is 40442422012.

It can be written as a sum of positive squares in 2 ways, for example, as 20035836304 + 986588100 = 141548^2 + 31410^2 .

It is a congruent number.

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, 381679 + ... + 433270.

It is an arithmetic number, because the mean of its divisors is an integer number (3066249375).

Almost surely, 2^21022424404 is an apocalyptic number.

It is an amenable number.

21022424404 is a deficient number, since it is larger than the sum of its proper divisors (15772568096).

21022424404 is a wasteful number, since it uses less digits than its factorization.

21022424404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 821402 (or 821400 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 25.

Adding to 21022424404 its reverse (40442422012), we get a palindrome (61464846416).

The spelling of 21022424404 in words is "twenty-one billion, twenty-two million, four hundred twenty-four thousand, four hundred four".