2661837649 has 3 divisors (see below), whose sum is σ = 2661889243. Its totient is φ = 2661786056.

The previous prime is 2661837631. The next prime is 2661837671. The reversal of 2661837649 is 9467381662.

The square root of 2661837649 is 51593.

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

2661837649 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 2648646225 + 13191424 = 51465^2 + 3632^2 .

It is not a de Polignac number, because 2661837649 - 2¹⁷ = 2661706577 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2661837596 and 2661837605.

It is not an unprimeable number, because it can be changed into a prime (2661837049) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 25797 + ... + 77389.

Almost surely, 2^2661837649 is an apocalyptic number.

2661837649 is the 51593-rd square number.

2661837649 is the 25797-th centered octagonal number.

It is an amenable number.

2661837649 is a deficient number, since it is larger than the sum of its proper divisors (51594).

2661837649 is an frugal number, since it uses more digits than its factorization.

2661837649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103186 (or 51593 counting only the distinct ones).

The product of its digits is 2612736, while the sum is 52.

The cubic root of 2661837649 is about 1385.8849794572.

The spelling of 2661837649 in words is "two billion, six hundred sixty-one million, eight hundred thirty-seven thousand, six hundred forty-nine".