21991855322 has 8 divisors (see below), whose sum is σ = 33358432500. Its totient is φ = 10872377824.

The previous prime is 21991855307. The next prime is 21991855337. The reversal of 21991855322 is 22355819912.

It is an interprime number because it is at equal distance from previous prime (21991855307) and next prime (21991855337).

It can be written as a sum of positive squares in 2 ways, for example, as 21158320681 + 833534641 = 145459^2 + 28871^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

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 3 ways as a sum of consecutive naturals, for example, 61774697 + ... + 61775052.

Almost surely, 2^21991855322 is an apocalyptic number.

21991855322 is a deficient number, since it is larger than the sum of its proper divisors (11366577178).

21991855322 is a wasteful number, since it uses less digits than its factorization.

21991855322 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123549840.

The product of its digits is 388800, while the sum is 47.

The spelling of 21991855322 in words is "twenty-one billion, nine hundred ninety-one million, eight hundred fifty-five thousand, three hundred twenty-two".