21991803448366 has 16 divisors (see below), whose sum is σ = 33541787371248. Its totient is φ = 10811350670400.

The previous prime is 21991803448339. The next prime is 21991803448393. The reversal of 21991803448366 is 66384430819912.

It is an interprime number because it is at equal distance from previous prime (21991803448339) and next prime (21991803448393).

It is a junction number, because it is equal to n+sod(n) for n = 21991803448298 and 21991803448307.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35444260 + ... + 36059383.

It is an arithmetic number, because the mean of its divisors is an integer number (2096361710703).

Almost surely, 2^{21991803448366} is an apocalyptic number.

21991803448366 is a deficient number, since it is larger than the sum of its proper divisors (11549983922882).

21991803448366 is a wasteful number, since it uses less digits than its factorization.

21991803448366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71506227.

The product of its (nonzero) digits is 53747712, while the sum is 64.

The spelling of 21991803448366 in words is "twenty-one trillion, nine hundred ninety-one billion, eight hundred three million, four hundred forty-eight thousand, three hundred sixty-six".