66409405 has 8 divisors (see below), whose sum is σ = 79884000. Its totient is φ = 52999056.

The previous prime is 66409403. The next prime is 66409411. The reversal of 66409405 is 50490466.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66409405 - 2¹ = 66409403 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66409403) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13755 + ... + 17944.

It is an arithmetic number, because the mean of its divisors is an integer number (9985500).

Almost surely, 2^66409405 is an apocalyptic number.

It is an amenable number.

66409405 is a deficient number, since it is larger than the sum of its proper divisors (13474595).

66409405 is a wasteful number, since it uses less digits than its factorization.

66409405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32123.

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 66409405 is about 8149.1965861673. The cubic root of 66409405 is about 404.9578882191.

The spelling of 66409405 in words is "sixty-six million, four hundred nine thousand, four hundred five".