83661521 has 2 divisors, whose sum is σ = 83661522. Its totient is φ = 83661520.

The previous prime is 83661509. The next prime is 83661527. The reversal of 83661521 is 12516638.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 76038400 + 7623121 = 8720^2 + 2761^2 .

It is a cyclic number.

It is not a de Polignac number, because 83661521 - 2¹⁰ = 83660497 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (83661527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41830760 + 41830761.

It is an arithmetic number, because the mean of its divisors is an integer number (41830761).

Almost surely, 2^83661521 is an apocalyptic number.

It is an amenable number.

83661521 is a deficient number, since it is larger than the sum of its proper divisors (1).

83661521 is an equidigital number, since it uses as much as digits as its factorization.

83661521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8640, while the sum is 32.

The square root of 83661521 is about 9146.6672072400. The cubic root of 83661521 is about 437.3628779526.

The spelling of 83661521 in words is "eighty-three million, six hundred sixty-one thousand, five hundred twenty-one".