16646640066 has 24 divisors (see below), whose sum is σ = 41220251904. Its totient is φ = 4756182840.

The previous prime is 16646640029. The next prime is 16646640071. The reversal of 16646640066 is 66004664661.

It is a super-2 number, since 2×16646640066² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 66057970 + ... + 66058221.

It is an arithmetic number, because the mean of its divisors is an integer number (1717510496).

Almost surely, 2^16646640066 is an apocalyptic number.

16646640066 is an abundant number, since it is smaller than the sum of its proper divisors (24573611838).

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

16646640066 is a wasteful number, since it uses less digits than its factorization.

16646640066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132116206 (or 132116203 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 45.

The spelling of 16646640066 in words is "sixteen billion, six hundred forty-six million, six hundred forty thousand, sixty-six".