66494409 has 4 divisors (see below), whose sum is σ = 88659216. Its totient is φ = 44329604.

The previous prime is 66494399. The next prime is 66494423. The reversal of 66494409 is 90449466.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66494409 - 2¹⁵ = 66461641 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66494479) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11082399 + ... + 11082404.

It is an arithmetic number, because the mean of its divisors is an integer number (22164804).

Almost surely, 2^66494409 is an apocalyptic number.

It is an amenable number.

66494409 is a deficient number, since it is larger than the sum of its proper divisors (22164807).

66494409 is a wasteful number, since it uses less digits than its factorization.

66494409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22164806.

The product of its (nonzero) digits is 186624, while the sum is 42.

The square root of 66494409 is about 8154.4104017397. The cubic root of 66494409 is about 405.1305965054.

The spelling of 66494409 in words is "sixty-six million, four hundred ninety-four thousand, four hundred nine".