209682483921 has 45 divisors (see below), whose sum is σ = 317566757739. Its totient is φ = 137878833744.

The previous prime is 209682483841. The next prime is 209682483929. The reversal of 209682483921 is 129384286902.

The square root of 209682483921 is 457911.

It is a perfect power (a square), and thus also a powerful number.

209682483921 is a `hidden beast` number, since 2 + 0 + 9 + 6 + 8 + 248 + 392 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 683561025 + 208998922896 = 26145^2 + 457164^2 .

It is not a de Polignac number, because 209682483921 - 2⁷ = 209682483793 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (209682483929) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 342059211 + ... + 342059823.

Almost surely, 2^209682483921 is an apocalyptic number.

209682483921 is the 457911-st square number.

209682483921 is the 228956-th centered octagonal number.

It is an amenable number.

209682483921 is a deficient number, since it is larger than the sum of its proper divisors (107884273818).

209682483921 is an frugal number, since it uses more digits than its factorization.

209682483921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1404 (or 699 counting only the distinct ones).

The product of its (nonzero) digits is 2985984, while the sum is 54.

The spelling of 209682483921 in words is "two hundred nine billion, six hundred eighty-two million, four hundred eighty-three thousand, nine hundred twenty-one".