83605661 has 4 divisors (see below), whose sum is σ = 83682972. Its totient is φ = 83528352.

The previous prime is 83605657. The next prime is 83605663. The reversal of 83605661 is 16650638.

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 38514436 + 45091225 = 6206^2 + 6715^2 .

It is a cyclic number.

It is not a de Polignac number, because 83605661 - 2² = 83605657 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (83605663) 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 3 ways as a sum of consecutive naturals, for example, 37010 + ... + 39203.

It is an arithmetic number, because the mean of its divisors is an integer number (20920743).

Almost surely, 2^83605661 is an apocalyptic number.

It is an amenable number.

83605661 is a deficient number, since it is larger than the sum of its proper divisors (77311).

83605661 is a wasteful number, since it uses less digits than its factorization.

83605661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77310.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 83605661 is about 9143.6131261116. The cubic root of 83605661 is about 437.2655152720.

The spelling of 83605661 in words is "eighty-three million, six hundred five thousand, six hundred sixty-one".