1630720643 has 2 divisors, whose sum is σ = 1630720644. Its totient is φ = 1630720642.

The previous prime is 1630720639. The next prime is 1630720673. The reversal of 1630720643 is 3460270361.

It is a weak prime.

It is an emirp because it is prime and its reverse (3460270361) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1630720643 - 2² = 1630720639 is a prime.

It is not a weakly prime, because it can be changed into another prime (1630720673) 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, 815360321 + 815360322.

It is an arithmetic number, because the mean of its divisors is an integer number (815360322).

Almost surely, 2^1630720643 is an apocalyptic number.

1630720643 is a deficient number, since it is larger than the sum of its proper divisors (1).

1630720643 is an equidigital number, since it uses as much as digits as its factorization.

1630720643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 32.

The square root of 1630720643 is about 40382.1822466295. The cubic root of 1630720643 is about 1177.0453328520.

The spelling of 1630720643 in words is "one billion, six hundred thirty million, seven hundred twenty thousand, six hundred forty-three".