66700400667 has 16 divisors (see below), whose sum is σ = 90859041792. Its totient is φ = 43505033600.

The previous prime is 66700400653. The next prime is 66700400747. The reversal of 66700400667 is 76600400766.

It is a cyclic number.

It is not a de Polignac number, because 66700400667 - 2¹¹ = 66700398619 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66700400617) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 310498 + ... + 479384.

It is an arithmetic number, because the mean of its divisors is an integer number (5678690112).

Almost surely, 2^66700400667 is an apocalyptic number.

66700400667 is a deficient number, since it is larger than the sum of its proper divisors (24158641125).

66700400667 is a wasteful number, since it uses less digits than its factorization.

66700400667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171738.

The product of its (nonzero) digits is 254016, while the sum is 42.

Subtracting 66700400667 from its reverse (76600400766), we obtain a palindrome (9900000099).

The spelling of 66700400667 in words is "sixty-six billion, seven hundred million, four hundred thousand, six hundred sixty-seven".