66063989 has 4 divisors (see below), whose sum is σ = 69950124. Its totient is φ = 62177856.

The previous prime is 66063983. The next prime is 66064043. The reversal of 66063989 is 98936066.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 37920964 + 28143025 = 6158^2 + 5305^2 .

It is a cyclic number.

It is not a de Polignac number, because 66063989 - 2¹⁶ = 65998453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66063983) 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, 1943042 + ... + 1943075.

It is an arithmetic number, because the mean of its divisors is an integer number (17487531).

Almost surely, 2^66063989 is an apocalyptic number.

It is an amenable number.

66063989 is a deficient number, since it is larger than the sum of its proper divisors (3886135).

66063989 is a wasteful number, since it uses less digits than its factorization.

66063989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3886134.

The product of its (nonzero) digits is 419904, while the sum is 47.

The square root of 66063989 is about 8127.9757012432. The cubic root of 66063989 is about 404.2545633657.

The spelling of 66063989 in words is "sixty-six million, sixty-three thousand, nine hundred eighty-nine".