2561917 has 8 divisors (see below), whose sum is σ = 2786616. Its totient is φ = 2345472.

The previous prime is 2561899. The next prime is 2561921. The reversal of 2561917 is 7191652.

It can be written as a sum of positive squares in 4 ways, for example, as 682276 + 1879641 = 826^2 + 1371^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2561917 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561927) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1408 + ... + 2665.

It is an arithmetic number, because the mean of its divisors is an integer number (348327).

2^2561917 is an apocalyptic number.

It is an amenable number.

2561917 is a deficient number, since it is larger than the sum of its proper divisors (224699).

2561917 is a wasteful number, since it uses less digits than its factorization.

2561917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4127.

The product of its digits is 3780, while the sum is 31.

The square root of 2561917 is about 1600.5989503933. The cubic root of 2561917 is about 136.8322132967.

The spelling of 2561917 in words is "two million, five hundred sixty-one thousand, nine hundred seventeen".