3661866323509 has 16 divisors (see below), whose sum is σ = 3835934340480. Its totient is φ = 3489040779840.

The previous prime is 3661866323473. The next prime is 3661866323527. The reversal of 3661866323509 is 9053236681663.

It is a cyclic number.

It is not a de Polignac number, because 3661866323509 - 2¹⁷ = 3661866192437 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3661866323009) 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, 38788654 + ... + 38882944.

It is an arithmetic number, because the mean of its divisors is an integer number (239745896280).

Almost surely, 2^{3661866323509} is an apocalyptic number.

It is an amenable number.

3661866323509 is a deficient number, since it is larger than the sum of its proper divisors (174068016971).

3661866323509 is a wasteful number, since it uses less digits than its factorization.

3661866323509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100860.

The product of its (nonzero) digits is 25194240, while the sum is 58.

The spelling of 3661866323509 in words is "three trillion, six hundred sixty-one billion, eight hundred sixty-six million, three hundred twenty-three thousand, five hundred nine".