18156681621066 has 16 divisors (see below), whose sum is σ = 36810806575104. Its totient is φ = 5969319984864.

The previous prime is 18156681621053. The next prime is 18156681621107. The reversal of 18156681621066 is 66012618665181.

It is a super-2 number, since 2×18156681621066² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18156681620997 and 18156681621015.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20726805066 + ... + 20726805941.

It is an arithmetic number, because the mean of its divisors is an integer number (2300675410944).

Almost surely, 2^{18156681621066} is an apocalyptic number.

18156681621066 is an abundant number, since it is smaller than the sum of its proper divisors (18654124954038).

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

18156681621066 is a wasteful number, since it uses less digits than its factorization.

18156681621066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41453611085.

The product of its (nonzero) digits is 4976640, while the sum is 57.

The spelling of 18156681621066 in words is "eighteen trillion, one hundred fifty-six billion, six hundred eighty-one million, six hundred twenty-one thousand, sixty-six".