209129666790 has 64 divisors (see below), whose sum is σ = 547745587200. Its totient is φ = 50679018240.

The previous prime is 209129666777. The next prime is 209129666791. The reversal of 209129666790 is 97666921902.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 209129666790.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209129666791) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 768786 + ... + 1004634.

It is an arithmetic number, because the mean of its divisors is an integer number (8558524800).

Almost surely, 2^209129666790 is an apocalyptic number.

209129666790 is an abundant number, since it is smaller than the sum of its proper divisors (338615920410).

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

209129666790 is a wasteful number, since it uses less digits than its factorization.

209129666790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238557.

The product of its (nonzero) digits is 4408992, while the sum is 57.

The spelling of 209129666790 in words is "two hundred nine billion, one hundred twenty-nine million, six hundred sixty-six thousand, seven hundred ninety".