1641563591 has 2 divisors, whose sum is σ = 1641563592. Its totient is φ = 1641563590.

The previous prime is 1641563579. The next prime is 1641563597. The reversal of 1641563591 is 1953651461.

It is a strong prime.

It is an emirp because it is prime and its reverse (1953651461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1641563591 - 2¹⁴ = 1641547207 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1641563597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820781795 + 820781796.

It is an arithmetic number, because the mean of its divisors is an integer number (820781796).

Almost surely, 2^1641563591 is an apocalyptic number.

1641563591 is a deficient number, since it is larger than the sum of its proper divisors (1).

1641563591 is an equidigital number, since it uses as much as digits as its factorization.

1641563591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 97200, while the sum is 41.

The square root of 1641563591 is about 40516.2139272662. The cubic root of 1641563591 is about 1179.6483657317.

The spelling of 1641563591 in words is "one billion, six hundred forty-one million, five hundred sixty-three thousand, five hundred ninety-one".