2661906749 has 8 divisors (see below), whose sum is σ = 2677410648. Its totient is φ = 2646423360.

The previous prime is 2661906743. The next prime is 2661906757. The reversal of 2661906749 is 9476091662.

It can be written as a sum of positive squares in 4 ways, for example, as 1205339524 + 1456567225 = 34718^2 + 38165^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2661906749 - 2¹⁶ = 2661841213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2661906697 and 2661906706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2661906743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 310379 + ... + 318839.

It is an arithmetic number, because the mean of its divisors is an integer number (334676331).

Almost surely, 2^2661906749 is an apocalyptic number.

It is an amenable number.

2661906749 is a deficient number, since it is larger than the sum of its proper divisors (15503899).

2661906749 is a wasteful number, since it uses less digits than its factorization.

2661906749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10255.

The product of its (nonzero) digits is 979776, while the sum is 50.

The square root of 2661906749 is about 51593.6696601434. The cubic root of 2661906749 is about 1385.8969716516.

The spelling of 2661906749 in words is "two billion, six hundred sixty-one million, nine hundred six thousand, seven hundred forty-nine".