209820923424 has 768 divisors, whose sum is σ = 772208640000. Its totient is φ = 54073184256.

The previous prime is 209820923423. The next prime is 209820923441. The reversal of 209820923424 is 424329028902.

209820923424 is a `hidden beast` number, since 209 + 8 + 209 + 234 + 2 + 4 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 209820923424.

It is not an unprimeable number, because it can be changed into a prime (209820923423) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 263262994 + ... + 263263790.

It is an arithmetic number, because the mean of its divisors is an integer number (1005480000).

Almost surely, 2^209820923424 is an apocalyptic number.

209820923424 is a gapful number since it is divisible by the number (24) 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 209820923424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (386104320000).

209820923424 is an abundant number, since it is smaller than the sum of its proper divisors (562387716576).

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

209820923424 is a wasteful number, since it uses less digits than its factorization.

209820923424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 950 (or 936 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 45.

The spelling of 209820923424 in words is "two hundred nine billion, eight hundred twenty million, nine hundred twenty-three thousand, four hundred twenty-four".