216172018853656 has 8 divisors (see below), whose sum is σ = 405322535350620. Its totient is φ = 108086009426824.

The previous prime is 216172018853641. The next prime is 216172018853657. The reversal of 216172018853656 is 656358810271612.

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 216172018853594 and 216172018853603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216172018853657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13510751178346 + ... + 13510751178361.

Almost surely, 2^{216172018853656} is an apocalyptic number.

It is an amenable number.

216172018853656 is a deficient number, since it is larger than the sum of its proper divisors (189150516496964).

216172018853656 is a wasteful number, since it uses less digits than its factorization.

216172018853656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27021502356713 (or 27021502356709 counting only the distinct ones).

The product of its (nonzero) digits is 29030400, while the sum is 61.

The spelling of 216172018853656 in words is "two hundred sixteen trillion, one hundred seventy-two billion, eighteen million, eight hundred fifty-three thousand, six hundred fifty-six".