21668533350 has 24 divisors (see below), whose sum is σ = 53737963080. Its totient is φ = 5778275520.

The previous prime is 21668533339. The next prime is 21668533351. The reversal of 21668533350 is 5333586612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21668533351) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 72228295 + ... + 72228594.

It is an arithmetic number, because the mean of its divisors is an integer number (2239081795).

Almost surely, 2^21668533350 is an apocalyptic number.

21668533350 is an abundant number, since it is smaller than the sum of its proper divisors (32069429730).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21668533350 is a wasteful number, since it uses less digits than its factorization.

21668533350 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144456904 (or 144456899 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 42.

The spelling of 21668533350 in words is "twenty-one billion, six hundred sixty-eight million, five hundred thirty-three thousand, three hundred fifty".