1643155123 has 2 divisors, whose sum is σ = 1643155124. Its totient is φ = 1643155122.

The previous prime is 1643155117. The next prime is 1643155141. The reversal of 1643155123 is 3215513461.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1643155123 - 2¹⁷ = 1643024051 is a prime.

It is a super-2 number, since 2×1643155123² = 5399917516482290258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1643155103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 821577561 + 821577562.

It is an arithmetic number, because the mean of its divisors is an integer number (821577562).

Almost surely, 2^1643155123 is an apocalyptic number.

1643155123 is a deficient number, since it is larger than the sum of its proper divisors (1).

1643155123 is an equidigital number, since it uses as much as digits as its factorization.

1643155123 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10800, while the sum is 31.

The square root of 1643155123 is about 40535.8498492384. The cubic root of 1643155123 is about 1180.0294742710.

Adding to 1643155123 its reverse (3215513461), we get a palindrome (4858668584).

The spelling of 1643155123 in words is "one billion, six hundred forty-three million, one hundred fifty-five thousand, one hundred twenty-three".