39336181981 has 2 divisors, whose sum is σ = 39336181982. Its totient is φ = 39336181980.

The previous prime is 39336181967. The next prime is 39336182089. The reversal of 39336181981 is 18918163393.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20841541956 + 18494640025 = 144366^2 + 135995^2 .

It is a cyclic number.

It is not a de Polignac number, because 39336181981 - 2²⁷ = 39201964253 is a prime.

It is a super-2 number, since 2×39336181981² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39336182981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19668090990 + 19668090991.

It is an arithmetic number, because the mean of its divisors is an integer number (19668090991).

Almost surely, 2^39336181981 is an apocalyptic number.

It is an amenable number.

39336181981 is a deficient number, since it is larger than the sum of its proper divisors (1).

39336181981 is an equidigital number, since it uses as much as digits as its factorization.

39336181981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 839808, while the sum is 52.

The spelling of 39336181981 in words is "thirty-nine billion, three hundred thirty-six million, one hundred eighty-one thousand, nine hundred eighty-one".