399139453481 has 2 divisors, whose sum is σ = 399139453482. Its totient is φ = 399139453480.

The previous prime is 399139453421. The next prime is 399139453487. The reversal of 399139453481 is 184354931993.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 367822842256 + 31316611225 = 606484^2 + 176965^2 .

It is an emirp because it is prime and its reverse (184354931993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 399139453481 - 2³⁸ = 124261546537 is a prime.

It is a super-2 number, since 2×399139453481² (a number of 24 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 399139453481.

It is not a weakly prime, because it can be changed into another prime (399139453487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199569726740 + 199569726741.

It is an arithmetic number, because the mean of its divisors is an integer number (199569726741).

Almost surely, 2^399139453481 is an apocalyptic number.

It is an amenable number.

399139453481 is a deficient number, since it is larger than the sum of its proper divisors (1).

399139453481 is an equidigital number, since it uses as much as digits as its factorization.

399139453481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12597120, while the sum is 59.

The spelling of 399139453481 in words is "three hundred ninety-nine billion, one hundred thirty-nine million, four hundred fifty-three thousand, four hundred eighty-one".