66770649891 has 48 divisors (see below), whose sum is σ = 110077269120. Its totient is φ = 40108763520.

The previous prime is 66770649839. The next prime is 66770649893. The reversal of 66770649891 is 19894607766.

It is not a de Polignac number, because 66770649891 - 2¹¹ = 66770647843 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66770649893) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 191520 + ... + 412578.

It is an arithmetic number, because the mean of its divisors is an integer number (2293276440).

Almost surely, 2^66770649891 is an apocalyptic number.

66770649891 is a deficient number, since it is larger than the sum of its proper divisors (43306619229).

66770649891 is a wasteful number, since it uses less digits than its factorization.

66770649891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221198 (or 221186 counting only the distinct ones).

The product of its (nonzero) digits is 27433728, while the sum is 63.

The spelling of 66770649891 in words is "sixty-six billion, seven hundred seventy million, six hundred forty-nine thousand, eight hundred ninety-one".