191531479 has 2 divisors, whose sum is σ = 191531480. Its totient is φ = 191531478.

The previous prime is 191531449. The next prime is 191531551. The reversal of 191531479 is 974135191.

It is a weak prime.

It is an emirp because it is prime and its reverse (974135191) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191531479 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191531429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95765739 + 95765740.

It is an arithmetic number, because the mean of its divisors is an integer number (95765740).

Almost surely, 2^191531479 is an apocalyptic number.

191531479 is a deficient number, since it is larger than the sum of its proper divisors (1).

191531479 is an equidigital number, since it uses as much as digits as its factorization.

191531479 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34020, while the sum is 40.

The square root of 191531479 is about 13839.4898388633. The cubic root of 191531479 is about 576.4301929880.

The spelling of 191531479 in words is "one hundred ninety-one million, five hundred thirty-one thousand, four hundred seventy-nine".