1645907841 has 12 divisors (see below), whose sum is σ = 2378298468. Its totient is φ = 1096867584.

The previous prime is 1645907827. The next prime is 1645907843. The reversal of 1645907841 is 1487095461.

1645907841 is a `hidden beast` number, since 16 + 4 + 590 + 7 + 8 + 41 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 226803600 + 1419104241 = 15060^2 + 37671^2 .

It is not a de Polignac number, because 1645907841 - 2⁶ = 1645907777 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (1645907843) 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 in 11 ways as a sum of consecutive naturals, for example, 6780 + ... + 57773.

It is an arithmetic number, because the mean of its divisors is an integer number (198191539).

Almost surely, 2^1645907841 is an apocalyptic number.

It is an amenable number.

1645907841 is a deficient number, since it is larger than the sum of its proper divisors (732390627).

1645907841 is a wasteful number, since it uses less digits than its factorization.

1645907841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67392 (or 67389 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The square root of 1645907841 is about 40569.7897578974. The cubic root of 1645907841 is about 1180.6880601225.

The spelling of 1645907841 in words is "one billion, six hundred forty-five million, nine hundred seven thousand, eight hundred forty-one".