1640243123 has 2 divisors, whose sum is σ = 1640243124. Its totient is φ = 1640243122.

The previous prime is 1640243069. The next prime is 1640243167. The reversal of 1640243123 is 3213420461.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1640243123 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1640243092 and 1640243101.

It is not a weakly prime, because it can be changed into another prime (1640243023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820121561 + 820121562.

It is an arithmetic number, because the mean of its divisors is an integer number (820121562).

Almost surely, 2^1640243123 is an apocalyptic number.

1640243123 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640243123 is an equidigital number, since it uses as much as digits as its factorization.

1640243123 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 1640243123 is about 40499.9150986764. The cubic root of 1640243123 is about 1179.3319792126.

Adding to 1640243123 its reverse (3213420461), we get a palindrome (4853663584).

The spelling of 1640243123 in words is "one billion, six hundred forty million, two hundred forty-three thousand, one hundred twenty-three".