83531621 has 2 divisors, whose sum is σ = 83531622. Its totient is φ = 83531620.

The previous prime is 83531599. The next prime is 83531689. The reversal of 83531621 is 12613538.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77704225 + 5827396 = 8815^2 + 2414^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-83531621 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (83531321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41765810 + 41765811.

It is an arithmetic number, because the mean of its divisors is an integer number (41765811).

Almost surely, 2^83531621 is an apocalyptic number.

It is an amenable number.

83531621 is a deficient number, since it is larger than the sum of its proper divisors (1).

83531621 is an equidigital number, since it uses as much as digits as its factorization.

83531621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 29.

The square root of 83531621 is about 9139.5635016121. The cubic root of 83531621 is about 437.1363984153.

The spelling of 83531621 in words is "eighty-three million, five hundred thirty-one thousand, six hundred twenty-one".