2531605 has 8 divisors (see below), whose sum is σ = 3072600. Its totient is φ = 2002176.

The previous prime is 2531593. The next prime is 2531609. The reversal of 2531605 is 5061352.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 463761 + 2067844 = 681^2 + 1438^2 .

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 2531605 - 2⁹ = 2531093 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2531609) 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, 2400 + ... + 3289.

It is an arithmetic number, because the mean of its divisors is an integer number (384075).

2^2531605 is an apocalyptic number.

It is an amenable number.

2531605 is a deficient number, since it is larger than the sum of its proper divisors (540995).

2531605 is an equidigital number, since it uses as much as digits as its factorization.

2531605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5783.

The product of its (nonzero) digits is 900, while the sum is 22.

The square root of 2531605 is about 1591.1018194949. The cubic root of 2531605 is about 136.2904153035.

Adding to 2531605 its reverse (5061352), we get a palindrome (7592957).

It can be divided in two parts, 2531 and 605, that added together give a square (3136 = 56²).

The spelling of 2531605 in words is "two million, five hundred thirty-one thousand, six hundred five".