2031561 has 20 divisors (see below), whose sum is σ = 3469312. Its totient is φ = 1160568.

The previous prime is 2031541. The next prime is 2031563. The reversal of 2031561 is 1651302.

It is not a de Polignac number, because 2031561 - 2¹³ = 2023369 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2031563) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1225 + ... + 2358.

2^2031561 is an apocalyptic number.

2031561 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2031561 is a deficient number, since it is larger than the sum of its proper divisors (1437751).

2031561 is an equidigital number, since it uses as much as digits as its factorization.

2031561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3602 (or 3593 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 2031561 is about 1425.3283832156. The cubic root of 2031561 is about 126.6513885851.

Adding to 2031561 its reverse (1651302), we get a palindrome (3682863).

It can be divided in two parts, 203 and 1561, that added together give a square (1764 = 42²).

The spelling of 2031561 in words is "two million, thirty-one thousand, five hundred sixty-one".