16661004212 has 6 divisors (see below), whose sum is σ = 29156757378. Its totient is φ = 8330502104.

The previous prime is 16661004211. The next prime is 16661004229. The reversal of 16661004212 is 21240016661.

It can be written as a sum of positive squares in only one way, i.e., 15295258276 + 1365745936 = 123674^2 + 36956^2 .

It is a super-2 number, since 2×16661004212² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16661004211) by changing a digit.

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 as a sum of consecutive naturals, namely, 2082625523 + ... + 2082625530.

It is an arithmetic number, because the mean of its divisors is an integer number (4859459563).

Almost surely, 2^16661004212 is an apocalyptic number.

It is an amenable number.

16661004212 is a deficient number, since it is larger than the sum of its proper divisors (12495753166).

16661004212 is a wasteful number, since it uses less digits than its factorization.

16661004212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4165251057 (or 4165251055 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The spelling of 16661004212 in words is "sixteen billion, six hundred sixty-one million, four thousand, two hundred twelve".