1645630741 has 2 divisors, whose sum is σ = 1645630742. Its totient is φ = 1645630740.

The previous prime is 1645630739. The next prime is 1645630757. The reversal of 1645630741 is 1470365461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1439823025 + 205807716 = 37945^2 + 14346^2 .

It is a cyclic number.

It is not a de Polignac number, because 1645630741 - 2¹ = 1645630739 is a prime.

Together with 1645630739, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1645630741.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1645634741) 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, 822815370 + 822815371.

It is an arithmetic number, because the mean of its divisors is an integer number (822815371).

Almost surely, 2^1645630741 is an apocalyptic number.

It is an amenable number.

1645630741 is a deficient number, since it is larger than the sum of its proper divisors (1).

1645630741 is an equidigital number, since it uses as much as digits as its factorization.

1645630741 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60480, while the sum is 37.

The square root of 1645630741 is about 40566.3745114103. The cubic root of 1645630741 is about 1180.6217973959.

The spelling of 1645630741 in words is "one billion, six hundred forty-five million, six hundred thirty thousand, seven hundred forty-one".