66722290 has 8 divisors (see below), whose sum is σ = 120100140. Its totient is φ = 26688912.

The previous prime is 66722213. The next prime is 66722291. The reversal of 66722290 is 9222766.

It can be written as a sum of positive squares in 2 ways, for example, as 53479969 + 13242321 = 7313^2 + 3639^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (66722291) 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, 3336105 + ... + 3336124.

Almost surely, 2^66722290 is an apocalyptic number.

66722290 is a deficient number, since it is larger than the sum of its proper divisors (53377850).

66722290 is a wasteful number, since it uses less digits than its factorization.

66722290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6672236.

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 66722290 is about 8168.3713186902. The cubic root of 66722290 is about 405.5928724723.

The spelling of 66722290 in words is "sixty-six million, seven hundred twenty-two thousand, two hundred ninety".