83661509 has 2 divisors, whose sum is σ = 83661510. Its totient is φ = 83661508.

The previous prime is 83661497. The next prime is 83661521. The reversal of 83661509 is 90516638.

It is a balanced prime because it is at equal distance from previous prime (83661497) and next prime (83661521).

It can be written as a sum of positive squares in only one way, i.e., 81396484 + 2265025 = 9022^2 + 1505^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-83661509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (83661559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41830754 + 41830755.

It is an arithmetic number, because the mean of its divisors is an integer number (41830755).

Almost surely, 2^83661509 is an apocalyptic number.

It is an amenable number.

83661509 is a deficient number, since it is larger than the sum of its proper divisors (1).

83661509 is an equidigital number, since it uses as much as digits as its factorization.

83661509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38880, while the sum is 38.

The square root of 83661509 is about 9146.6665512634. Note that the first 3 decimals coincide. The cubic root of 83661509 is about 437.3628570416.

The spelling of 83661509 in words is "eighty-three million, six hundred sixty-one thousand, five hundred nine".