83640591 has 6 divisors (see below), whose sum is σ = 120814200. Its totient is φ = 55760388.

The previous prime is 83640587. The next prime is 83640593. The reversal of 83640591 is 19504638.

83640591 is a `hidden beast` number, since 8 + 3 + 64 + 0 + 591 = 666.

It is not a de Polignac number, because 83640591 - 2² = 83640587 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (83640593) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4646691 + ... + 4646708.

It is an arithmetic number, because the mean of its divisors is an integer number (20135700).

Almost surely, 2^83640591 is an apocalyptic number.

83640591 is a deficient number, since it is larger than the sum of its proper divisors (37173609).

83640591 is a wasteful number, since it uses less digits than its factorization.

83640591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9293405 (or 9293402 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 83640591 is about 9145.5230030874. The cubic root of 83640591 is about 437.3264025280.

The spelling of 83640591 in words is "eighty-three million, six hundred forty thousand, five hundred ninety-one".