21222504742 has 4 divisors (see below), whose sum is σ = 31833757116. Its totient is φ = 10611252370.

The previous prime is 21222504713. The next prime is 21222504767. The reversal of 21222504742 is 24740522212.

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

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5305626184 + ... + 5305626187.

It is an arithmetic number, because the mean of its divisors is an integer number (7958439279).

Almost surely, 2^21222504742 is an apocalyptic number.

21222504742 is a deficient number, since it is larger than the sum of its proper divisors (10611252374).

21222504742 is a wasteful number, since it uses less digits than its factorization.

21222504742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10611252373.

The product of its (nonzero) digits is 17920, while the sum is 31.

The spelling of 21222504742 in words is "twenty-one billion, two hundred twenty-two million, five hundred four thousand, seven hundred forty-two".