1643607155 has 32 divisors (see below), whose sum is σ = 2078265600. Its totient is φ = 1246371840.

The previous prime is 1643607151. The next prime is 1643607157. The reversal of 1643607155 is 5517063461.

It is not a de Polignac number, because 1643607155 - 2² = 1643607151 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1643607151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3660371 + ... + 3660819.

It is an arithmetic number, because the mean of its divisors is an integer number (64945800).

Almost surely, 2^1643607155 is an apocalyptic number.

1643607155 is a deficient number, since it is larger than the sum of its proper divisors (434658445).

1643607155 is a wasteful number, since it uses less digits than its factorization.

1643607155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 959.

The product of its (nonzero) digits is 75600, while the sum is 38.

The square root of 1643607155 is about 40541.4251722852. The cubic root of 1643607155 is about 1180.1376730587.

The spelling of 1643607155 in words is "one billion, six hundred forty-three million, six hundred seven thousand, one hundred fifty-five".