3666212321 has 4 divisors (see below), whose sum is σ = 3666495252. Its totient is φ = 3665929392.

The previous prime is 3666212311. The next prime is 3666212353. The reversal of 3666212321 is 1232126663.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1232126663 = 17 ⋅72478039.

It can be written as a sum of positive squares in 2 ways, for example, as 781985296 + 2884227025 = 27964^2 + 53705^2 .

It is a cyclic number.

It is not a de Polignac number, because 3666212321 - 2⁶ = 3666212257 is a prime.

It is a super-2 number, since 2×3666212321² = 26882225565304414082, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3666212311) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121046 + ... + 148271.

It is an arithmetic number, because the mean of its divisors is an integer number (916623813).

Almost surely, 2^3666212321 is an apocalyptic number.

It is an amenable number.

3666212321 is a deficient number, since it is larger than the sum of its proper divisors (282931).

3666212321 is a wasteful number, since it uses less digits than its factorization.

3666212321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 282930.

The product of its digits is 15552, while the sum is 32.

The square root of 3666212321 is about 60549.2553298552. The cubic root of 3666212321 is about 1541.9579752000.

Adding to 3666212321 its reverse (1232126663), we get a palindrome (4898338984).

The spelling of 3666212321 in words is "three billion, six hundred sixty-six million, two hundred twelve thousand, three hundred twenty-one".