2661405445 has 4 divisors (see below), whose sum is σ = 3193686540. Its totient is φ = 2129124352.

The previous prime is 2661405433. The next prime is 2661405451. The reversal of 2661405445 is 5445041662.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1445976676 + 1215428769 = 38026^2 + 34863^2 .

It is a cyclic number.

It is not a de Polignac number, because 2661405445 - 2⁷ = 2661405317 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266140540 + ... + 266140549.

It is an arithmetic number, because the mean of its divisors is an integer number (798421635).

Almost surely, 2^2661405445 is an apocalyptic number.

It is an amenable number.

2661405445 is a deficient number, since it is larger than the sum of its proper divisors (532281095).

2661405445 is an equidigital number, since it uses as much as digits as its factorization.

2661405445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 532281094.

The product of its (nonzero) digits is 115200, while the sum is 37.

The square root of 2661405445 is about 51588.8112384846. The cubic root of 2661405445 is about 1385.8099664358.

The spelling of 2661405445 in words is "two billion, six hundred sixty-one million, four hundred five thousand, four hundred forty-five".