209920891110 has 32 divisors (see below), whose sum is σ = 575783016192. Its totient is φ = 47981917920.

The previous prime is 209920891097. The next prime is 209920891111. The reversal of 209920891110 is 11198029902.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209920891111) 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, 499811436 + ... + 499811855.

It is an arithmetic number, because the mean of its divisors is an integer number (17993219256).

Almost surely, 2^209920891110 is an apocalyptic number.

209920891110 is an abundant number, since it is smaller than the sum of its proper divisors (365862125082).

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

209920891110 is a wasteful number, since it uses less digits than its factorization.

209920891110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 999623308.

The product of its (nonzero) digits is 23328, while the sum is 42.

The spelling of 209920891110 in words is "two hundred nine billion, nine hundred twenty million, eight hundred ninety-one thousand, one hundred ten".