12191231531 has 2 divisors, whose sum is σ = 12191231532. Its totient is φ = 12191231530.

The previous prime is 12191231519. The next prime is 12191231587. The reversal of 12191231531 is 13513219121.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 12191231531 - 2¹⁴ = 12191215147 is a prime.

It is a super-2 number, since 2×12191231531² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 12191231494 and 12191231503.

It is not a weakly prime, because it can be changed into another prime (12191231431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6095615765 + 6095615766.

It is an arithmetic number, because the mean of its divisors is an integer number (6095615766).

Almost surely, 2^12191231531 is an apocalyptic number.

12191231531 is a deficient number, since it is larger than the sum of its proper divisors (1).

12191231531 is an equidigital number, since it uses as much as digits as its factorization.

12191231531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1620, while the sum is 29.

The spelling of 12191231531 in words is "twelve billion, one hundred ninety-one million, two hundred thirty-one thousand, five hundred thirty-one".