39661943 has 2 divisors, whose sum is σ = 39661944. Its totient is φ = 39661942.

The previous prime is 39661933. The next prime is 39661981. The reversal of 39661943 is 34916693.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 39661943 - 2¹⁶ = 39596407 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 39661943.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39661903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19830971 + 19830972.

It is an arithmetic number, because the mean of its divisors is an integer number (19830972).

Almost surely, 2^39661943 is an apocalyptic number.

39661943 is a deficient number, since it is larger than the sum of its proper divisors (1).

39661943 is an equidigital number, since it uses as much as digits as its factorization.

39661943 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 104976, while the sum is 41.

The square root of 39661943 is about 6297.7728603055. The cubic root of 39661943 is about 341.0290134497.

It can be divided in two parts, 39661 and 943, that added together give a palindrome (40604).

The spelling of 39661943 in words is "thirty-nine million, six hundred sixty-one thousand, nine hundred forty-three".