66661038406 has 16 divisors (see below), whose sum is σ = 100163398608. Its totient is φ = 33273268000.

The previous prime is 66661038397. The next prime is 66661038421. The reversal of 66661038406 is 60483016666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8718021 + ... + 8725663.

It is an arithmetic number, because the mean of its divisors is an integer number (6260212413).

Almost surely, 2^66661038406 is an apocalyptic number.

66661038406 is a deficient number, since it is larger than the sum of its proper divisors (33502360202).

66661038406 is a wasteful number, since it uses less digits than its factorization.

66661038406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14567.

The product of its (nonzero) digits is 746496, while the sum is 46.

The spelling of 66661038406 in words is "sixty-six billion, six hundred sixty-one million, thirty-eight thousand, four hundred six".