2561738 has 4 divisors (see below), whose sum is σ = 3842610. Its totient is φ = 1280868.

The previous prime is 2561737. The next prime is 2561743. The reversal of 2561738 is 8371652.

It is a happy number.

2561738 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.

It can be written as a sum of positive squares in only one way, i.e., 1423249 + 1138489 = 1193^2 + 1067^2 .

It is not an unprimeable number, because it can be changed into a prime (2561731) 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 as a sum of consecutive naturals, namely, 640433 + ... + 640436.

2^2561738 is an apocalyptic number.

2561738 is a deficient number, since it is larger than the sum of its proper divisors (1280872).

2561738 is a wasteful number, since it uses less digits than its factorization.

2561738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1280871.

The product of its digits is 10080, while the sum is 32.

The square root of 2561738 is about 1600.5430328485. The cubic root of 2561738 is about 136.8290264205.

The spelling of 2561738 in words is "two million, five hundred sixty-one thousand, seven hundred thirty-eight".