1680641591 has 2 divisors, whose sum is σ = 1680641592. Its totient is φ = 1680641590.

The previous prime is 1680641587. The next prime is 1680641593. The reversal of 1680641591 is 1951460861.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1680641591 - 2² = 1680641587 is a prime.

It is a super-2 number, since 2×1680641591² = 5649112314798022562, which contains 22 as substring.

Together with 1680641593, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1680641593) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840320795 + 840320796.

It is an arithmetic number, because the mean of its divisors is an integer number (840320796).

Almost surely, 2^1680641591 is an apocalyptic number.

1680641591 is a deficient number, since it is larger than the sum of its proper divisors (1).

1680641591 is an equidigital number, since it uses as much as digits as its factorization.

1680641591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51840, while the sum is 41.

The square root of 1680641591 is about 40995.6289255330. The cubic root of 1680641591 is about 1188.9357033092.

The spelling of 1680641591 in words is "one billion, six hundred eighty million, six hundred forty-one thousand, five hundred ninety-one".