1138810531 has 4 divisors (see below), whose sum is σ = 1169589232. Its totient is φ = 1108031832.

The previous prime is 1138810511. The next prime is 1138810549. The reversal of 1138810531 is 1350188311.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1350188311 = 131 ⋅10306781.

It is a cyclic number.

It is not a de Polignac number, because 1138810531 - 2¹⁵ = 1138777763 is a prime.

It is a super-2 number, since 2×1138810531² = 2593778851033003922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1138810493 and 1138810502.

It is not an unprimeable number, because it can be changed into a prime (1138810511) 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, 15389295 + ... + 15389368.

It is an arithmetic number, because the mean of its divisors is an integer number (292397308).

Almost surely, 2^1138810531 is an apocalyptic number.

1138810531 is a deficient number, since it is larger than the sum of its proper divisors (30778701).

1138810531 is an equidigital number, since it uses as much as digits as its factorization.

1138810531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30778700.

The product of its (nonzero) digits is 2880, while the sum is 31.

The square root of 1138810531 is about 33746.2669194683. The cubic root of 1138810531 is about 1044.2804753657.

Adding to 1138810531 its reverse (1350188311), we get a palindrome (2488998842).

The spelling of 1138810531 in words is "one billion, one hundred thirty-eight million, eight hundred ten thousand, five hundred thirty-one".