1231530520531 has 16 divisors (see below), whose sum is σ = 1290980423520. Its totient is φ = 1173709405440.

The previous prime is 1231530520511. The next prime is 1231530520541. The reversal of 1231530520531 is 1350250351321.

It is a cyclic number.

It is not a de Polignac number, because 1231530520531 - 2¹⁷ = 1231530389459 is a prime.

It is a super-2 number, since 2×1231530520531² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1231530520493 and 1231530520502.

It is not an unprimeable number, because it can be changed into a prime (1231530520511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1395240 + ... + 2099941.

It is an arithmetic number, because the mean of its divisors is an integer number (80686276470).

Almost surely, 2^{1231530520531} is an apocalyptic number.

1231530520531 is a deficient number, since it is larger than the sum of its proper divisors (59449902989).

1231530520531 is a wasteful number, since it uses less digits than its factorization.

1231530520531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3495414.

The product of its (nonzero) digits is 13500, while the sum is 31.

Adding to 1231530520531 its reverse (1350250351321), we get a palindrome (2581780871852).

The spelling of 1231530520531 in words is "one trillion, two hundred thirty-one billion, five hundred thirty million, five hundred twenty thousand, five hundred thirty-one".