66238690 has 24 divisors (see below), whose sum is σ = 138696732. Its totient is φ = 22710240.

The previous prime is 66238687. The next prime is 66238699. The reversal of 66238690 is 9683266.

It can be written as a sum of positive squares in 2 ways, for example, as 62900761 + 3337929 = 7931^2 + 1827^2 .

It is a super-2 number, since 2×66238690² = 8775128105832200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (66238699) 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, 67101 + ... + 68080.

Almost surely, 2^66238690 is an apocalyptic number.

66238690 is an abundant number, since it is smaller than the sum of its proper divisors (72458042).

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

66238690 is a wasteful number, since it uses less digits than its factorization.

66238690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135202 (or 135195 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 40.

The square root of 66238690 is about 8138.7155006180. The cubic root of 66238690 is about 404.6105894747.

The spelling of 66238690 in words is "sixty-six million, two hundred thirty-eight thousand, six hundred ninety".