66546891 has 12 divisors (see below), whose sum is σ = 101777832. Its totient is φ = 41754816.

The previous prime is 66546841. The next prime is 66546919. The reversal of 66546891 is 19864566.

It is not a de Polignac number, because 66546891 - 2⁷ = 66546763 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (66546811) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 217321 + ... + 217626.

It is an arithmetic number, because the mean of its divisors is an integer number (8481486).

Almost surely, 2^66546891 is an apocalyptic number.

66546891 is a deficient number, since it is larger than the sum of its proper divisors (35230941).

66546891 is a wasteful number, since it uses less digits than its factorization.

66546891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 434970 (or 434967 counting only the distinct ones).

The product of its digits is 311040, while the sum is 45.

The square root of 66546891 is about 8157.6277801822. The cubic root of 66546891 is about 405.2371541990.

The spelling of 66546891 in words is "sixty-six million, five hundred forty-six thousand, eight hundred ninety-one".