2561247 has 16 divisors (see below), whose sum is σ = 4086880. Its totient is φ = 1575936.

The previous prime is 2561239. The next prime is 2561261. The reversal of 2561247 is 7421652.

2561247 is a `hidden beast` number, since 2 + 5 + 612 + 47 = 666.

It is not a de Polignac number, because 2561247 - 2³ = 2561239 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

2561247 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 2561247.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3298 + ... + 3999.

It is an arithmetic number, because the mean of its divisors is an integer number (255430).

2^2561247 is an apocalyptic number.

2561247 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

2561247 is a deficient number, since it is larger than the sum of its proper divisors (1525633).

2561247 is a wasteful number, since it uses less digits than its factorization.

2561247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7319 (or 7313 counting only the distinct ones).

The product of its digits is 3360, while the sum is 27.

The square root of 2561247 is about 1600.3896400564. The cubic root of 2561247 is about 136.8202840036.

Adding to 2561247 its reverse (7421652), we get a palindrome (9982899).

The spelling of 2561247 in words is "two million, five hundred sixty-one thousand, two hundred forty-seven".