66440415 has 16 divisors (see below), whose sum is σ = 106481376. Its totient is φ = 35376000.

The previous prime is 66440401. The next prime is 66440447. The reversal of 66440415 is 51404466.

It is not a de Polignac number, because 66440415 - 2⁵ = 66440383 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6565 + ... + 13265.

It is an arithmetic number, because the mean of its divisors is an integer number (6655086).

Almost surely, 2^66440415 is an apocalyptic number.

66440415 is a deficient number, since it is larger than the sum of its proper divisors (40040961).

66440415 is a wasteful number, since it uses less digits than its factorization.

66440415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7370.

The product of its (nonzero) digits is 11520, while the sum is 30.

The square root of 66440415 is about 8151.0990056556. The cubic root of 66440415 is about 405.0209103668.

The spelling of 66440415 in words is "sixty-six million, four hundred forty thousand, four hundred fifteen".