1601605 has 16 divisors (see below), whose sum is σ = 2113920. Its totient is φ = 1159488.

The previous prime is 1601599. The next prime is 1601609. The reversal of 1601605 is 5061061.

It is a cyclic number.

It is not a de Polignac number, because 1601605 - 2⁵ = 1601573 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1601609) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1819 + ... + 2551.

It is an arithmetic number, because the mean of its divisors is an integer number (132120).

2^1601605 is an apocalyptic number.

It is an amenable number.

1601605 is a deficient number, since it is larger than the sum of its proper divisors (512315).

1601605 is a wasteful number, since it uses less digits than its factorization.

1601605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 780.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 1601605 is about 1265.5453369990. The cubic root of 1601605 is about 116.9998051961. Note that the first 3 decimals are identical.

Adding to 1601605 its reverse (5061061), we get a palindrome (6662666).

The spelling of 1601605 in words is "one million, six hundred one thousand, six hundred five".