209120878926 has 80 divisors (see below), whose sum is σ = 470836119600. Its totient is φ = 69372702720.

The previous prime is 209120878909. The next prime is 209120878951. The reversal of 209120878926 is 629878021902.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 77479525 + ... + 77482223.

It is an arithmetic number, because the mean of its divisors is an integer number (5885451495).

Almost surely, 2^209120878926 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 209120878926, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (235418059800).

209120878926 is an abundant number, since it is smaller than the sum of its proper divisors (261715240674).

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

209120878926 is a wasteful number, since it uses less digits than its factorization.

209120878926 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4831 (or 4822 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 54.

The spelling of 209120878926 in words is "two hundred nine billion, one hundred twenty million, eight hundred seventy-eight thousand, nine hundred twenty-six".