209122028640 has 1152 divisors, whose sum is σ = 915195939840. Its totient is φ = 44019376128.

The previous prime is 209122028639. The next prime is 209122028693. The reversal of 209122028640 is 46820221902.

209122028640 is a `hidden beast` number, since 2 + 0 + 9 + 1 + 2 + 2 + 0 + 2 + 8 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 209122028595 and 209122028604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 191327934 + ... + 191329026.

It is an arithmetic number, because the mean of its divisors is an integer number (794440920).

Almost surely, 2^209122028640 is an apocalyptic number.

209122028640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 209122028640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (457597969920).

209122028640 is an abundant number, since it is smaller than the sum of its proper divisors (706073911200).

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

209122028640 is a wasteful number, since it uses less digits than its factorization.

209122028640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1186 (or 1166 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The spelling of 209122028640 in words is "two hundred nine billion, one hundred twenty-two million, twenty-eight thousand, six hundred forty".