66651563 has 8 divisors (see below), whose sum is σ = 76537920. Its totient is φ = 57403080.

The previous prime is 66651553. The next prime is 66651583. The reversal of 66651563 is 36515666.

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 66651563 - 2⁴ = 66651547 is a prime.

It is a super-3 number, since 3×66651563³ (a number of 24 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66651503) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 159245 + ... + 159662.

It is an arithmetic number, because the mean of its divisors is an integer number (9567240).

Almost surely, 2^66651563 is an apocalyptic number.

66651563 is a deficient number, since it is larger than the sum of its proper divisors (9886357).

66651563 is a wasteful number, since it uses less digits than its factorization.

66651563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318937.

The product of its digits is 97200, while the sum is 38.

The square root of 66651563 is about 8164.0408499713. The cubic root of 66651563 is about 405.4495095416.

It can be divided in two parts, 6665 and 1563, that added together give a palindrome (8228).

The spelling of 66651563 in words is "sixty-six million, six hundred fifty-one thousand, five hundred sixty-three".