21224496385 has 4 divisors (see below), whose sum is σ = 25469395668. Its totient is φ = 16979597104.

The previous prime is 21224496317. The next prime is 21224496427. The reversal of 21224496385 is 58369442212.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5418726544 + 15805769841 = 73612^2 + 125721^2 .

It is a cyclic number.

It is not a de Polignac number, because 21224496385 - 2¹³ = 21224488193 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2122449634 + ... + 2122449643.

It is an arithmetic number, because the mean of its divisors is an integer number (6367348917).

Almost surely, 2^21224496385 is an apocalyptic number.

It is an amenable number.

21224496385 is a deficient number, since it is larger than the sum of its proper divisors (4244899283).

21224496385 is an equidigital number, since it uses as much as digits as its factorization.

21224496385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4244899282.

The product of its digits is 829440, while the sum is 46.

The spelling of 21224496385 in words is "twenty-one billion, two hundred twenty-four million, four hundred ninety-six thousand, three hundred eighty-five".