2131531 has 2 divisors, whose sum is σ = 2131532. Its totient is φ = 2131530.

The previous prime is 2131517. The next prime is 2131537. The reversal of 2131531 is 1351312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2131531 - 2¹⁵ = 2098763 is a prime.

It is a super-2 number, since 2×2131531² = 9086848807922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2131537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1065765 + 1065766.

It is an arithmetic number, because the mean of its divisors is an integer number (1065766).

2^2131531 is an apocalyptic number.

2131531 is a deficient number, since it is larger than the sum of its proper divisors (1).

2131531 is an equidigital number, since it uses as much as digits as its factorization.

2131531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90, while the sum is 16.

The square root of 2131531 is about 1459.9763696718. The cubic root of 2131531 is about 128.6956549479.

Adding to 2131531 its reverse (1351312), we get a palindrome (3482843).

It can be divided in two parts, 2131 and 531, that added together give a palindrome (2662).

The spelling of 2131531 in words is "two million, one hundred thirty-one thousand, five hundred thirty-one".