1606821841 has 4 divisors (see below), whose sum is σ = 1607899572. Its totient is φ = 1605744112.

The previous prime is 1606821833. The next prime is 1606821863. The reversal of 1606821841 is 1481286061.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 802532241 + 804289600 = 28329^2 + 28360^2 .

It is a cyclic number.

It is not a de Polignac number, because 1606821841 - 2³ = 1606821833 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1606821841.

It is not an unprimeable number, because it can be changed into a prime (1606821341) 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, 536626 + ... + 539611.

It is an arithmetic number, because the mean of its divisors is an integer number (401974893).

Almost surely, 2^1606821841 is an apocalyptic number.

It is an amenable number.

1606821841 is a deficient number, since it is larger than the sum of its proper divisors (1077731).

1606821841 is a wasteful number, since it uses less digits than its factorization.

1606821841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1077730.

The product of its (nonzero) digits is 18432, while the sum is 37.

The square root of 1606821841 is about 40085.1823121712. The cubic root of 1606821841 is about 1171.2670037666.

The spelling of 1606821841 in words is "one billion, six hundred six million, eight hundred twenty-one thousand, eight hundred forty-one".