21663604342246 has 4 divisors (see below), whose sum is σ = 32495406513372. Its totient is φ = 10831802171122.

The previous prime is 21663604342243. The next prime is 21663604342253. The reversal of 21663604342246 is 64224340636612.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21663604342246.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21663604342243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5415901085560 + ... + 5415901085563.

It is an arithmetic number, because the mean of its divisors is an integer number (8123851628343).

Almost surely, 2^{21663604342246} is an apocalyptic number.

21663604342246 is a deficient number, since it is larger than the sum of its proper divisors (10831802171126).

21663604342246 is a wasteful number, since it uses less digits than its factorization.

21663604342246 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10831802171125.

The product of its (nonzero) digits is 5971968, while the sum is 49.

Adding to 21663604342246 its reverse (64224340636612), we get a palindrome (85887944978858).

The spelling of 21663604342246 in words is "twenty-one trillion, six hundred sixty-three billion, six hundred four million, three hundred forty-two thousand, two hundred forty-six".