2101531 has 2 divisors, whose sum is σ = 2101532. Its totient is φ = 2101530.

The previous prime is 2101513. The next prime is 2101549. The reversal of 2101531 is 1351012.

Together with previous prime (2101513) it forms an Ormiston pair, because they use the same digits, order apart.

It is a balanced prime because it is at equal distance from previous prime (2101513) and next prime (2101549).

It is a cyclic number.

It is not a de Polignac number, because 2101531 - 2⁵ = 2101499 is a prime.

It is a super-2 number, since 2×2101531² = 8832865087922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2101501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050765 + 1050766.

It is an arithmetic number, because the mean of its divisors is an integer number (1050766).

2^2101531 is an apocalyptic number.

2101531 is a deficient number, since it is larger than the sum of its proper divisors (1).

2101531 is an equidigital number, since it uses as much as digits as its factorization.

2101531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30, while the sum is 13.

The square root of 2101531 is about 1449.6658235607. The cubic root of 2101531 is about 128.0890290455.

Adding to 2101531 its reverse (1351012), we get a palindrome (3452543).

The spelling of 2101531 in words is "two million, one hundred one thousand, five hundred thirty-one".