663993399366 has 96 divisors (see below), whose sum is σ = 1620151708032. Its totient is φ = 194791322880.

The previous prime is 663993399337. The next prime is 663993399371.

663993399366 is a `hidden beast` number, since 6 + 63 + 99 + 33 + 99 + 366 = 666.

663993399366 is nontrivially palindromic in base 10.

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 = 663993399294 and 663993399303.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 617001 + ... + 1307163.

It is an arithmetic number, because the mean of its divisors is an integer number (16876580292).

Almost surely, 2^663993399366 is an apocalyptic number.

663993399366 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 663993399366, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (810075854016).

663993399366 is an abundant number, since it is smaller than the sum of its proper divisors (956158308666).

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

663993399366 is a wasteful number, since it uses less digits than its factorization.

663993399366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 690338 (or 690335 counting only the distinct ones).

The product of its digits is 688747536, while the sum is 72.

The spelling of 663993399366 in words is "six hundred sixty-three billion, nine hundred ninety-three million, three hundred ninety-nine thousand, three hundred sixty-six".