66409057 has 24 divisors (see below), whose sum is σ = 79319520. Its totient is φ = 55111680.

The previous prime is 66409019. The next prime is 66409061. The reversal of 66409057 is 75090466.

It is not a de Polignac number, because 66409057 - 2¹¹ = 66407009 is a prime.

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66409087) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 258273 + ... + 258529.

It is an arithmetic number, because the mean of its divisors is an integer number (3304980).

Almost surely, 2^66409057 is an apocalyptic number.

It is an amenable number.

66409057 is a deficient number, since it is larger than the sum of its proper divisors (12910463).

66409057 is a wasteful number, since it uses less digits than its factorization.

66409057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433 (or 420 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 37.

The square root of 66409057 is about 8149.1752343412. The cubic root of 66409057 is about 404.9571808615.

The spelling of 66409057 in words is "sixty-six million, four hundred nine thousand, fifty-seven".