66563461994 has 8 divisors (see below), whose sum is σ = 99934583268. Its totient is φ = 33251934240.

The previous prime is 66563461973. The next prime is 66563461999. The reversal of 66563461994 is 49916436566.

It can be written as a sum of positive squares in 2 ways, for example, as 57306135769 + 9257326225 = 239387^2 + 96215^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (66563461999) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14895587 + ... + 14900054.

Almost surely, 2^66563461994 is an apocalyptic number.

66563461994 is a deficient number, since it is larger than the sum of its proper divisors (33371121274).

66563461994 is a wasteful number, since it uses less digits than its factorization.

66563461994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29796760.

The product of its digits is 25194240, while the sum is 59.

The spelling of 66563461994 in words is "sixty-six billion, five hundred sixty-three million, four hundred sixty-one thousand, nine hundred ninety-four".