1641194491 has 2 divisors, whose sum is σ = 1641194492. Its totient is φ = 1641194490.

The previous prime is 1641194437. The next prime is 1641194531. The reversal of 1641194491 is 1944911461.

It is an a-pointer prime, because the next prime (1641194531) can be obtained adding 1641194491 to its sum of digits (40).

It is a strong prime.

It is an emirp because it is prime and its reverse (1944911461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1641194491 - 2⁹ = 1641193979 is a prime.

It is not a weakly prime, because it can be changed into another prime (1641114491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820597245 + 820597246.

It is an arithmetic number, because the mean of its divisors is an integer number (820597246).

Almost surely, 2^1641194491 is an apocalyptic number.

1641194491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1641194491 is an equidigital number, since it uses as much as digits as its factorization.

1641194491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 40.

The square root of 1641194491 is about 40511.6587046248. The cubic root of 1641194491 is about 1179.5599457944.

The spelling of 1641194491 in words is "one billion, six hundred forty-one million, one hundred ninety-four thousand, four hundred ninety-one".