2661512321 has 16 divisors (see below), whose sum is σ = 2996241024. Its totient is φ = 2345739264.

The previous prime is 2661512311. The next prime is 2661512339. The reversal of 2661512321 is 1232151662.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2661512321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2661512311) 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, 164810 + ... + 180236.

It is an arithmetic number, because the mean of its divisors is an integer number (187265064).

Almost surely, 2^2661512321 is an apocalyptic number.

It is an amenable number.

2661512321 is a deficient number, since it is larger than the sum of its proper divisors (334728703).

2661512321 is a wasteful number, since it uses less digits than its factorization.

2661512321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16040.

The product of its digits is 4320, while the sum is 29.

The square root of 2661512321 is about 51589.8470728495. The cubic root of 2661512321 is about 1385.8285165148.

Adding to 2661512321 its reverse (1232151662), we get a palindrome (3893663983).

The spelling of 2661512321 in words is "two billion, six hundred sixty-one million, five hundred twelve thousand, three hundred twenty-one".