66998065 has 8 divisors (see below), whose sum is σ = 80441640. Its totient is φ = 53569152.

The previous prime is 66998027. The next prime is 66998081. The reversal of 66998065 is 56089966.

It can be written as a sum of positive squares in 4 ways, for example, as 4129024 + 62869041 = 2032^2 + 7929^2 .

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 66998065 - 2⁷ = 66997937 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15747 + ... + 19543.

It is an arithmetic number, because the mean of its divisors is an integer number (10055205).

Almost surely, 2^66998065 is an apocalyptic number.

It is an amenable number.

66998065 is a deficient number, since it is larger than the sum of its proper divisors (13443575).

66998065 is a wasteful number, since it uses less digits than its factorization.

66998065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7331.

The product of its (nonzero) digits is 699840, while the sum is 49.

The square root of 66998065 is about 8185.2345720816. The cubic root of 66998065 is about 406.1509000091.

The spelling of 66998065 in words is "sixty-six million, nine hundred ninety-eight thousand, sixty-five".