66651318 has 24 divisors (see below), whose sum is σ = 144689688. Its totient is φ = 22174272.

The previous prime is 66651317. The next prime is 66651323. The reversal of 66651318 is 81315666.

It is a happy number.

It is a super-2 number, since 2×66651318² = 8884796382274248, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66651317) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6846 + ... + 13422.

It is an arithmetic number, because the mean of its divisors is an integer number (6028737).

Almost surely, 2^66651318 is an apocalyptic number.

66651318 is an abundant number, since it is smaller than the sum of its proper divisors (78038370).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66651318 is a wasteful number, since it uses less digits than its factorization.

66651318 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7148 (or 7145 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 66651318 is about 8164.0258451330. The cubic root of 66651318 is about 405.4490127528.

It can be divided in two parts, 666 and 51318, that added together give a square (51984 = 228²).

The spelling of 66651318 in words is "sixty-six million, six hundred fifty-one thousand, three hundred eighteen".