3261666321 has 9 divisors (see below), whose sum is σ = 4711543291. Its totient is φ = 2174329992.

The previous prime is 3261666319. The next prime is 3261666347. The reversal of 3261666321 is 1236661623.

The square root of 3261666321 is 57111.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 16769025 + 3244897296 = 4095^2 + 56964^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 3261666321 - 2¹ = 3261666319 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3261666301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 161815 + ... + 180851.

Almost surely, 2^3261666321 is an apocalyptic number.

3261666321 is the 57111-st square number.

3261666321 is the 28556-th centered octagonal number.

It is an amenable number.

3261666321 is a deficient number, since it is larger than the sum of its proper divisors (1449876970).

3261666321 is an frugal number, since it uses more digits than its factorization.

3261666321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38080 (or 19040 counting only the distinct ones).

The product of its digits is 46656, while the sum is 36.

The cubic root of 3261666321 is about 1483.0182987184.

Multiplying 3261666321 by its sum of digits (36), we get a square (117419987556 = 342666²).

Multiplying 3261666321 by its product of digits (46656), we get a square (152176303872576 = 12335976²).

The spelling of 3261666321 in words is "three billion, two hundred sixty-one million, six hundred sixty-six thousand, three hundred twenty-one".