1641605 has 32 divisors (see below), whose sum is σ = 2488320. Its totient is φ = 1013760.

The previous prime is 1641593. The next prime is 1641613. The reversal of 1641605 is 5061461.

It is not a de Polignac number, because 1641605 - 2⁴ = 1641589 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18401 + ... + 18489.

It is an arithmetic number, because the mean of its divisors is an integer number (77760).

2^1641605 is an apocalyptic number.

It is an amenable number.

1641605 is a deficient number, since it is larger than the sum of its proper divisors (846715).

1641605 is a wasteful number, since it uses less digits than its factorization.

1641605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 1641605 is about 1281.2513414627. The cubic root of 1641605 is about 117.9658284659.

The spelling of 1641605 in words is "one million, six hundred forty-one thousand, six hundred five".