16661004205 has 16 divisors (see below), whose sum is σ = 20096022960. Its totient is φ = 13260436992.

The previous prime is 16661004203. The next prime is 16661004209. The reversal of 16661004205 is 50240016661.

It can be written as a sum of positive squares in 8 ways, for example, as 83411689 + 16577592516 = 9133^2 + 128754^2 .

It is a cyclic number.

It is not a de Polignac number, because 16661004205 - 2¹ = 16661004203 is a prime.

It is a super-2 number, since 2×16661004205² (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 (16661004203) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 761377 + ... + 782953.

It is an arithmetic number, because the mean of its divisors is an integer number (1256001435).

Almost surely, 2^16661004205 is an apocalyptic number.

It is an amenable number.

16661004205 is a deficient number, since it is larger than the sum of its proper divisors (3435018755).

16661004205 is a wasteful number, since it uses less digits than its factorization.

16661004205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22368.

The product of its (nonzero) digits is 8640, while the sum is 31.

The spelling of 16661004205 in words is "sixteen billion, six hundred sixty-one million, four thousand, two hundred five".