66722868 has 36 divisors (see below), whose sum is σ = 168908740. Its totient is φ = 22208256.

The previous prime is 66722861. The next prime is 66722891. The reversal of 66722868 is 86822766.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 40220964 + 26501904 = 6342^2 + 5148^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×66722868² = 8903882228290848, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66722861) 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, 45978 + ... + 47406.

Almost surely, 2^66722868 is an apocalyptic number.

It is an amenable number.

66722868 is an abundant number, since it is smaller than the sum of its proper divisors (102185872).

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

66722868 is a wasteful number, since it uses less digits than its factorization.

66722868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2736 (or 2731 counting only the distinct ones).

The product of its digits is 387072, while the sum is 45.

The square root of 66722868 is about 8168.4066989836. The cubic root of 66722868 is about 405.5940436552.

The spelling of 66722868 in words is "sixty-six million, seven hundred twenty-two thousand, eight hundred sixty-eight".