66819262464 has 72 divisors (see below), whose sum is σ = 192986350830. Its totient is φ = 22273081344.

The previous prime is 66819262463. The next prime is 66819262493. The reversal of 66819262464 is 46426291866.

66819262464 is a `hidden beast` number, since 6 + 6 + 8 + 1 + 9 + 2 + 624 + 6 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 52071588864 + 14747673600 = 228192^2 + 121440^2 .

It is a tau number, because it is divible by the number of its divisors (72).

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

It is a self number, because there is not a number n which added to its sum of digits gives 66819262464.

It is not an unprimeable number, because it can be changed into a prime (66819262463) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1794157 + ... + 1831020.

Almost surely, 2^66819262464 is an apocalyptic number.

66819262464 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

66819262464 is an abundant number, since it is smaller than the sum of its proper divisors (126167088366).

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

66819262464 is a wasteful number, since it uses less digits than its factorization.

66819262464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3625205 (or 3625182 counting only the distinct ones).

The product of its digits is 5971968, while the sum is 54.

The spelling of 66819262464 in words is "sixty-six billion, eight hundred nineteen million, two hundred sixty-two thousand, four hundred sixty-four".