66391801 has 16 divisors (see below), whose sum is σ = 80450560. Its totient is φ = 53576640.

The previous prime is 66391799. The next prime is 66391813. The reversal of 66391801 is 10819366.

It is a cyclic number.

It is not a de Polignac number, because 66391801 - 2¹ = 66391799 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66391861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3895 + ... + 12163.

It is an arithmetic number, because the mean of its divisors is an integer number (5028160).

Almost surely, 2^66391801 is an apocalyptic number.

It is an amenable number.

66391801 is a deficient number, since it is larger than the sum of its proper divisors (14058759).

66391801 is a wasteful number, since it uses less digits than its factorization.

66391801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8344.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 66391801 is about 8148.1164081032. The cubic root of 66391801 is about 404.9221025816.

The spelling of 66391801 in words is "sixty-six million, three hundred ninety-one thousand, eight hundred one".