39955942643 has 2 divisors, whose sum is σ = 39955942644. Its totient is φ = 39955942642.

The previous prime is 39955942603. The next prime is 39955942699. The reversal of 39955942643 is 34624955993.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (34624955993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 39955942643 - 2⁸ = 39955942387 is a prime.

It is not a weakly prime, because it can be changed into another prime (39955942603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19977971321 + 19977971322.

It is an arithmetic number, because the mean of its divisors is an integer number (19977971322).

Almost surely, 2^39955942643 is an apocalyptic number.

39955942643 is a deficient number, since it is larger than the sum of its proper divisors (1).

39955942643 is an equidigital number, since it uses as much as digits as its factorization.

39955942643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31492800, while the sum is 59.

The spelling of 39955942643 in words is "thirty-nine billion, nine hundred fifty-five million, nine hundred forty-two thousand, six hundred forty-three".