39894053981 has 2 divisors, whose sum is σ = 39894053982. Its totient is φ = 39894053980.

The previous prime is 39894053959. The next prime is 39894053989. The reversal of 39894053981 is 18935049893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24639580900 + 15254473081 = 156970^2 + 123509^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-39894053981 is a prime.

It is a super-2 number, since 2×39894053981² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 39894053981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39894053989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19947026990 + 19947026991.

It is an arithmetic number, because the mean of its divisors is an integer number (19947026991).

Almost surely, 2^39894053981 is an apocalyptic number.

It is an amenable number.

39894053981 is a deficient number, since it is larger than the sum of its proper divisors (1).

39894053981 is an equidigital number, since it uses as much as digits as its factorization.

39894053981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8398080, while the sum is 59.

The spelling of 39894053981 in words is "thirty-nine billion, eight hundred ninety-four million, fifty-three thousand, nine hundred eighty-one".