209920112640 has 576 divisors, whose sum is σ = 880437055680. Its totient is φ = 45156925440.

The previous prime is 209920112593. The next prime is 209920112653. The reversal of 209920112640 is 46211029902.

209920112640 is a `hidden beast` number, since 2 + 0 + 9 + 9 + 2 + 0 + 1 + 1 + 2 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

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 = 209920112595 and 209920112604.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 10957470 + ... + 10976610.

It is an arithmetic number, because the mean of its divisors is an integer number (1528536555).

Almost surely, 2^209920112640 is an apocalyptic number.

209920112640 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 209920112640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (440218527840).

209920112640 is an abundant number, since it is smaller than the sum of its proper divisors (670516943040).

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

209920112640 is a wasteful number, since it uses less digits than its factorization.

209920112640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19198 (or 19175 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The spelling of 209920112640 in words is "two hundred nine billion, nine hundred twenty million, one hundred twelve thousand, six hundred forty".