19131691531 has 2 divisors, whose sum is σ = 19131691532. Its totient is φ = 19131691530.

The previous prime is 19131691519. The next prime is 19131691547. The reversal of 19131691531 is 13519613191.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19131691531 is a prime.

It is a super-2 number, since 2×19131691531² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (19131691561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9565845765 + 9565845766.

It is an arithmetic number, because the mean of its divisors is an integer number (9565845766).

Almost surely, 2^19131691531 is an apocalyptic number.

19131691531 is a deficient number, since it is larger than the sum of its proper divisors (1).

19131691531 is an equidigital number, since it uses as much as digits as its factorization.

19131691531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21870, while the sum is 40.

The spelling of 19131691531 in words is "nineteen billion, one hundred thirty-one million, six hundred ninety-one thousand, five hundred thirty-one".