209221824 has 56 divisors (see below), whose sum is σ = 632651008. Its totient is φ = 59777280.

The previous prime is 209221819. The next prime is 209221871. The reversal of 209221824 is 428122902.

It is a tau number, because it is divible by the number of its divisors (56).

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 209221791 and 209221800.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76492 + ... + 79179.

Almost surely, 2^209221824 is an apocalyptic number.

209221824 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

209221824 is an abundant number, since it is smaller than the sum of its proper divisors (423429184).

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

209221824 is a wasteful number, since it uses less digits than its factorization.

209221824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155693 (or 155683 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 209221824 is about 14464.5022036709. The cubic root of 209221824 is about 593.6570932896.

The spelling of 209221824 in words is "two hundred nine million, two hundred twenty-one thousand, eight hundred twenty-four".