66209390 has 32 divisors (see below), whose sum is σ = 135898560. Its totient is φ = 23007744.

The previous prime is 66209389. The next prime is 66209393. The reversal of 66209390 is 9390266.

It is a self number, because there is not a number n which added to its sum of digits gives 66209390.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66209393) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12770 + ... + 17189.

It is an arithmetic number, because the mean of its divisors is an integer number (4246830).

Almost surely, 2^66209390 is an apocalyptic number.

66209390 is an abundant number, since it is smaller than the sum of its proper divisors (69689170).

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

66209390 is a wasteful number, since it uses less digits than its factorization.

66209390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29996.

The product of its (nonzero) digits is 17496, while the sum is 35.

The square root of 66209390 is about 8136.9152631695. The cubic root of 66209390 is about 404.5509222385.

The spelling of 66209390 in words is "sixty-six million, two hundred nine thousand, three hundred ninety".