399617777664 has 448 divisors, whose sum is σ = 1360968576000. Its totient is φ = 113515167744.

The previous prime is 399617777641. The next prime is 399617777677. The reversal of 399617777664 is 466777716993.

399617777664 is a `hidden beast` number, since 399 + 6 + 177 + 7 + 7 + 6 + 64 = 666.

It is a tau number, because it is divible by the number of its divisors (448).

It is a super-2 number, since 2×399617777664² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 399617777592 and 399617777601.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 308108664 + ... + 308109960.

Almost surely, 2^399617777664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399617777664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (680484288000).

399617777664 is an abundant number, since it is smaller than the sum of its proper divisors (961350798336).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

399617777664 is a wasteful number, since it uses less digits than its factorization.

399617777664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1538 (or 1508 counting only the distinct ones).

The product of its digits is 504094752, while the sum is 72.

The spelling of 399617777664 in words is "three hundred ninety-nine billion, six hundred seventeen million, seven hundred seventy-seven thousand, six hundred sixty-four".