1605623 has 4 divisors (see below), whose sum is σ = 1608528. Its totient is φ = 1602720.

The previous prime is 1605619. The next prime is 1605629. The reversal of 1605623 is 3265061.

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 1605623 - 2² = 1605619 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1605629) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 338 + ... + 1823.

It is an arithmetic number, because the mean of its divisors is an integer number (402132).

2^1605623 is an apocalyptic number.

1605623 is a deficient number, since it is larger than the sum of its proper divisors (2905).

1605623 is an equidigital number, since it uses as much as digits as its factorization.

1605623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2904.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 1605623 is about 1267.1318005638. The cubic root of 1605623 is about 117.0975639321.

The spelling of 1605623 in words is "one million, six hundred five thousand, six hundred twenty-three".