1918640423 has 6 divisors (see below), whose sum is σ = 2231887896. Its totient is φ = 1644548892.

The previous prime is 1918640419. The next prime is 1918640441. The reversal of 1918640423 is 3240468191.

It is not a de Polignac number, because 1918640423 - 2² = 1918640419 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1918640453) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 19577915 + ... + 19578012.

It is an arithmetic number, because the mean of its divisors is an integer number (371981316).

Almost surely, 2^1918640423 is an apocalyptic number.

1918640423 is a deficient number, since it is larger than the sum of its proper divisors (313247473).

1918640423 is an equidigital number, since it uses as much as digits as its factorization.

1918640423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39155941 (or 39155934 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 1918640423 is about 43802.2878740369. The cubic root of 1918640423 is about 1242.5995635352.

The spelling of 1918640423 in words is "one billion, nine hundred eighteen million, six hundred forty thousand, four hundred twenty-three".