2155605643 has 4 divisors (see below), whose sum is σ = 2155729288. Its totient is φ = 2155482000.

The previous prime is 2155605637. The next prime is 2155605659. The reversal of 2155605643 is 3465065512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2155605643 - 2¹⁷ = 2155474571 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2155605343) 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 3 ways as a sum of consecutive naturals, for example, 30321 + ... + 72322.

It is an arithmetic number, because the mean of its divisors is an integer number (538932322).

Almost surely, 2^2155605643 is an apocalyptic number.

2155605643 is a deficient number, since it is larger than the sum of its proper divisors (123645).

2155605643 is a wasteful number, since it uses less digits than its factorization.

2155605643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123644.

The product of its (nonzero) digits is 108000, while the sum is 37.

The square root of 2155605643 is about 46428.5003311544. The cubic root of 2155605643 is about 1291.7836119234.

The spelling of 2155605643 in words is "two billion, one hundred fifty-five million, six hundred five thousand, six hundred forty-three".