21224017774 has 32 divisors (see below), whose sum is σ = 32949007776. Its totient is φ = 10245657600.

The previous prime is 21224017769. The next prime is 21224017777. The reversal of 21224017774 is 47771042212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21224017777) by changing a digit.

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 in 15 ways as a sum of consecutive naturals, for example, 11783674 + ... + 11785474.

It is an arithmetic number, because the mean of its divisors is an integer number (1029656493).

Almost surely, 2^21224017774 is an apocalyptic number.

21224017774 is a deficient number, since it is larger than the sum of its proper divisors (11724990002).

21224017774 is a wasteful number, since it uses less digits than its factorization.

21224017774 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2980.

The product of its (nonzero) digits is 43904, while the sum is 37.

Adding to 21224017774 its reverse (47771042212), we get a palindrome (68995059986).

The spelling of 21224017774 in words is "twenty-one billion, two hundred twenty-four million, seventeen thousand, seven hundred seventy-four".