1606561605 has 24 divisors (see below), whose sum is σ = 3037862880. Its totient is φ = 778938720.

The previous prime is 1606561601. The next prime is 1606561609. The reversal of 1606561605 is 5061656061.

It is an interprime number because it is at equal distance from previous prime (1606561601) and next prime (1606561609).

It is not a de Polignac number, because 1606561605 - 2² = 1606561601 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1606561605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1606561601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1622295 + ... + 1623284.

It is an arithmetic number, because the mean of its divisors is an integer number (126577620).

Almost surely, 2^1606561605 is an apocalyptic number.

1606561605 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1606561605 is a deficient number, since it is larger than the sum of its proper divisors (1431301275).

1606561605 is a wasteful number, since it uses less digits than its factorization.

1606561605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3245601 (or 3245598 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The square root of 1606561605 is about 40081.9361433552. The cubic root of 1606561605 is about 1171.2037687335.

It can be divided in two parts, 160656 and 1605, that added together give a palindrome (162261).

The spelling of 1606561605 in words is "one billion, six hundred six million, five hundred sixty-one thousand, six hundred five".