399617777677 has 2 divisors, whose sum is σ = 399617777678. Its totient is φ = 399617777676.

The previous prime is 399617777641. The next prime is 399617777693. The reversal of 399617777677 is 776777716993.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 204906507556 + 194711270121 = 452666^2 + 441261^2 .

It is a cyclic number.

It is not a de Polignac number, because 399617777677 - 2⁷ = 399617777549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399617777617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199808888838 + 199808888839.

It is an arithmetic number, because the mean of its divisors is an integer number (199808888839).

Almost surely, 2^399617777677 is an apocalyptic number.

It is an amenable number.

399617777677 is a deficient number, since it is larger than the sum of its proper divisors (1).

399617777677 is an equidigital number, since it uses as much as digits as its factorization.

399617777677 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1029193452, while the sum is 76.

The spelling of 399617777677 in words is "three hundred ninety-nine billion, six hundred seventeen million, seven hundred seventy-seven thousand, six hundred seventy-seven".