191631563 has 2 divisors, whose sum is σ = 191631564. Its totient is φ = 191631562.

The previous prime is 191631541. The next prime is 191631569. The reversal of 191631563 is 365136191.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 191631563 - 2²² = 187437259 is a prime.

It is not a weakly prime, because it can be changed into another prime (191631569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95815781 + 95815782.

It is an arithmetic number, because the mean of its divisors is an integer number (95815782).

Almost surely, 2^191631563 is an apocalyptic number.

191631563 is a deficient number, since it is larger than the sum of its proper divisors (1).

191631563 is an equidigital number, since it uses as much as digits as its factorization.

191631563 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14580, while the sum is 35.

The square root of 191631563 is about 13843.1052513517. The cubic root of 191631563 is about 576.5305792601.

The spelling of 191631563 in words is "one hundred ninety-one million, six hundred thirty-one thousand, five hundred sixty-three".