1640423 has 2 divisors, whose sum is σ = 1640424. Its totient is φ = 1640422.

The previous prime is 1640399. The next prime is 1640447. The reversal of 1640423 is 3240461.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (1640399) and next prime (1640447).

It is a cyclic number.

It is not a de Polignac number, because 1640423 - 2⁸ = 1640167 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1640395 and 1640404.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1640323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820211 + 820212.

It is an arithmetic number, because the mean of its divisors is an integer number (820212).

2^1640423 is an apocalyptic number.

1640423 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640423 is an equidigital number, since it uses as much as digits as its factorization.

1640423 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 1640423 is about 1280.7899905917. The cubic root of 1640423 is about 117.9375088054.

Adding to 1640423 its reverse (3240461), we get a palindrome (4880884).

The spelling of 1640423 in words is "one million, six hundred forty thousand, four hundred twenty-three".