66065905 has 16 divisors (see below), whose sum is σ = 81913104. Its totient is φ = 51114240.

The previous prime is 66065903. The next prime is 66065911. The reversal of 66065905 is 50956066.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 7144929 + 58920976 = 2673^2 + 7676^2 .

It is not a de Polignac number, because 66065905 - 2¹ = 66065903 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66065903) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32499 + ... + 34471.

It is an arithmetic number, because the mean of its divisors is an integer number (5119569).

Almost surely, 2^66065905 is an apocalyptic number.

It is an amenable number.

66065905 is a deficient number, since it is larger than the sum of its proper divisors (15847199).

66065905 is a wasteful number, since it uses less digits than its factorization.

66065905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2196.

The product of its (nonzero) digits is 48600, while the sum is 37.

The square root of 66065905 is about 8128.0935649142. The cubic root of 66065905 is about 404.2584714164.

The spelling of 66065905 in words is "sixty-six million, sixty-five thousand, nine hundred five".