1645055979 has 24 divisors (see below), whose sum is σ = 2662456320. Its totient is φ = 899159184.

The previous prime is 1645055963. The next prime is 1645055989. The reversal of 1645055979 is 9795505461.

It is not a de Polignac number, because 1645055979 - 2⁴ = 1645055963 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1645055939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 239899 + ... + 246660.

It is an arithmetic number, because the mean of its divisors is an integer number (110935680).

Almost surely, 2^1645055979 is an apocalyptic number.

1645055979 is a deficient number, since it is larger than the sum of its proper divisors (1017400341).

1645055979 is a wasteful number, since it uses less digits than its factorization.

1645055979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 486599 (or 486592 counting only the distinct ones).

The product of its (nonzero) digits is 1701000, while the sum is 51.

The square root of 1645055979 is about 40559.2896757327. The cubic root of 1645055979 is about 1180.4843312469.

The spelling of 1645055979 in words is "one billion, six hundred forty-five million, fifty-five thousand, nine hundred seventy-nine".