21663393334 has 16 divisors (see below), whose sum is σ = 35458375680. Its totient is φ = 9844445160.

The previous prime is 21663393299. The next prime is 21663393373. The reversal of 21663393334 is 43339336612.

It is a happy number.

It is a super-2 number, since 2×21663393334² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39414 + ... + 211849.

It is an arithmetic number, because the mean of its divisors is an integer number (2216148480).

Almost surely, 2^21663393334 is an apocalyptic number.

21663393334 is a deficient number, since it is larger than the sum of its proper divisors (13794982346).

21663393334 is a wasteful number, since it uses less digits than its factorization.

21663393334 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255195.

The product of its digits is 629856, while the sum is 43.

The spelling of 21663393334 in words is "twenty-one billion, six hundred sixty-three million, three hundred ninety-three thousand, three hundred thirty-four".