1680621571 has 2 divisors, whose sum is σ = 1680621572. Its totient is φ = 1680621570.

The previous prime is 1680621557. The next prime is 1680621577. The reversal of 1680621571 is 1751260861.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1680621571 - 2²⁵ = 1647067139 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1680621571.

It is not a weakly prime, because it can be changed into another prime (1680621577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840310785 + 840310786.

It is an arithmetic number, because the mean of its divisors is an integer number (840310786).

Almost surely, 2^1680621571 is an apocalyptic number.

1680621571 is a deficient number, since it is larger than the sum of its proper divisors (1).

1680621571 is an equidigital number, since it uses as much as digits as its factorization.

1680621571 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20160, while the sum is 37.

The square root of 1680621571 is about 40995.3847524328. The cubic root of 1680621571 is about 1188.9309823766.

The spelling of 1680621571 in words is "one billion, six hundred eighty million, six hundred twenty-one thousand, five hundred seventy-one".