39985643 has 2 divisors, whose sum is σ = 39985644. Its totient is φ = 39985642.

The previous prime is 39985639. The next prime is 39985697. The reversal of 39985643 is 34658993.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 39985643 - 2² = 39985639 is a prime.

It is a super-3 number, since 3×39985643³ (a number of 24 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (39987643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19992821 + 19992822.

It is an arithmetic number, because the mean of its divisors is an integer number (19992822).

Almost surely, 2^39985643 is an apocalyptic number.

39985643 is a deficient number, since it is larger than the sum of its proper divisors (1).

39985643 is an equidigital number, since it uses as much as digits as its factorization.

39985643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 699840, while the sum is 47.

The square root of 39985643 is about 6323.4201979625. The cubic root of 39985643 is about 341.9542675646.

The spelling of 39985643 in words is "thirty-nine million, nine hundred eighty-five thousand, six hundred forty-three".