83645981 has 2 divisors, whose sum is σ = 83645982. Its totient is φ = 83645980.

The previous prime is 83645977. The next prime is 83645983. The reversal of 83645981 is 18954638.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78605956 + 5040025 = 8866^2 + 2245^2 .

It is a cyclic number.

It is not a de Polignac number, because 83645981 - 2² = 83645977 is a prime.

It is a super-2 number, since 2×83645981² = 13993300274904722, which contains 22 as substring.

Together with 83645983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (83645983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41822990 + 41822991.

It is an arithmetic number, because the mean of its divisors is an integer number (41822991).

Almost surely, 2^83645981 is an apocalyptic number.

It is an amenable number.

83645981 is a deficient number, since it is larger than the sum of its proper divisors (1).

83645981 is an equidigital number, since it uses as much as digits as its factorization.

83645981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 207360, while the sum is 44.

The square root of 83645981 is about 9145.8176780428. The cubic root of 83645981 is about 437.3357964465.

The spelling of 83645981 in words is "eighty-three million, six hundred forty-five thousand, nine hundred eighty-one".