31536121 has 4 divisors (see below), whose sum is σ = 31563252. Its totient is φ = 31508992.

The previous prime is 31536101. The next prime is 31536161. The reversal of 31536121 is 12163513.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12163513 = 569 ⋅21377.

It can be written as a sum of positive squares in 2 ways, for example, as 14930496 + 16605625 = 3864^2 + 4075^2 .

It is a cyclic number.

It is not a de Polignac number, because 31536121 - 2¹¹ = 31534073 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31536092 and 31536101.

It is not an unprimeable number, because it can be changed into a prime (31536101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11740 + ... + 14173.

It is an arithmetic number, because the mean of its divisors is an integer number (7890813).

Almost surely, 2^31536121 is an apocalyptic number.

It is an amenable number.

31536121 is a deficient number, since it is larger than the sum of its proper divisors (27131).

31536121 is a wasteful number, since it uses less digits than its factorization.

31536121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27130.

The product of its digits is 540, while the sum is 22.

The square root of 31536121 is about 5615.7030726348. The cubic root of 31536121 is about 315.9386497627.

Adding to 31536121 its reverse (12163513), we get a palindrome (43699634).

The spelling of 31536121 in words is "thirty-one million, five hundred thirty-six thousand, one hundred twenty-one".