21216042056366 has 8 divisors (see below), whose sum is σ = 31824082972200. Its totient is φ = 10608014398968.

The previous prime is 21216042056329. The next prime is 21216042056369. The reversal of 21216042056366 is 66365024061212.

It is a happy number.

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

It is a super-2 number, since 2×21216042056366² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21216042056369) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3433640 + ... + 7363556.

It is an arithmetic number, because the mean of its divisors is an integer number (3978010371525).

Almost surely, 2^{21216042056366} is an apocalyptic number.

21216042056366 is a deficient number, since it is larger than the sum of its proper divisors (10608040915834).

21216042056366 is a wasteful number, since it uses less digits than its factorization.

21216042056366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6629218.

The product of its (nonzero) digits is 622080, while the sum is 44.

The spelling of 21216042056366 in words is "twenty-one trillion, two hundred sixteen billion, forty-two million, fifty-six thousand, three hundred sixty-six".