399617777641 has 2 divisors, whose sum is σ = 399617777642. Its totient is φ = 399617777640.

The previous prime is 399617777633. The next prime is 399617777677. The reversal of 399617777641 is 146777716993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 200326961241 + 199290816400 = 447579^2 + 446420^2 .

It is an emirp because it is prime and its reverse (146777716993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 399617777641 - 2³ = 399617777633 is a prime.

It is not a weakly prime, because it can be changed into another prime (399617778641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199808888820 + 199808888821.

It is an arithmetic number, because the mean of its divisors is an integer number (199808888821).

Almost surely, 2^399617777641 is an apocalyptic number.

It is an amenable number.

399617777641 is a deficient number, since it is larger than the sum of its proper divisors (1).

399617777641 is an equidigital number, since it uses as much as digits as its factorization.

399617777641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 84015792, while the sum is 67.

The spelling of 399617777641 in words is "three hundred ninety-nine billion, six hundred seventeen million, seven hundred seventy-seven thousand, six hundred forty-one".