1005123131 has 4 divisors (see below), whose sum is σ = 1014881712. Its totient is φ = 995364552.

The previous prime is 1005123121. The next prime is 1005123139. The reversal of 1005123131 is 1313215001.

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

It is a cyclic number.

It is not a de Polignac number, because 1005123131 - 2²² = 1000928827 is a prime.

It is a super-2 number, since 2×1005123131² = 2020545016942486322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1005123139) 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, 4879136 + ... + 4879341.

It is an arithmetic number, because the mean of its divisors is an integer number (253720428).

Almost surely, 2^1005123131 is an apocalyptic number.

1005123131 is a deficient number, since it is larger than the sum of its proper divisors (9758581).

1005123131 is an equidigital number, since it uses as much as digits as its factorization.

1005123131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9758580.

The product of its (nonzero) digits is 90, while the sum is 17.

The square root of 1005123131 is about 31703.6769318639. The cubic root of 1005123131 is about 1001.7048023308.

Adding to 1005123131 its reverse (1313215001), we get a palindrome (2318338132).

The spelling of 1005123131 in words is "one billion, five million, one hundred twenty-three thousand, one hundred thirty-one".