2015531 has 4 divisors (see below), whose sum is σ = 2303472. Its totient is φ = 1727592.

The previous prime is 2015509. The next prime is 2015543. The reversal of 2015531 is 1355102.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2015531 is a prime.

It is a super-2 number, since 2×2015531² = 8124730423922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2015731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 143960 + ... + 143973.

It is an arithmetic number, because the mean of its divisors is an integer number (575868).

2^2015531 is an apocalyptic number.

2015531 is a deficient number, since it is larger than the sum of its proper divisors (287941).

2015531 is an equidigital number, since it uses as much as digits as its factorization.

2015531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287940.

The product of its (nonzero) digits is 150, while the sum is 17.

The square root of 2015531 is about 1419.6939811100. The cubic root of 2015531 is about 126.3173949875.

It can be divided in two parts, 20 and 15531, that added together give a palindrome (15551).

The spelling of 2015531 in words is "two million, fifteen thousand, five hundred thirty-one".