243630100921 has 27 divisors (see below), whose sum is σ = 253901653551. Its totient is φ = 233771647824.

The previous prime is 243630100871. The next prime is 243630100933. The reversal of 243630100921 is 129001036342.

The square root of 243630100921 is 493589.

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

It can be written as a sum of positive squares in only one way, i.e., 175632237225 + 67997863696 = 419085^2 + 260764^2 .

It is not a de Polignac number, because 243630100921 - 2¹³ = 243630092729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243630100121) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1752734470 + ... + 1752734608.

Almost surely, 2^243630100921 is an apocalyptic number.

243630100921 is the 493589-th square number.

243630100921 is the 246795-th centered octagonal number.

It is an amenable number.

243630100921 is a deficient number, since it is larger than the sum of its proper divisors (10271552630).

243630100921 is an frugal number, since it uses more digits than its factorization.

243630100921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 518 (or 259 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 31.

The spelling of 243630100921 in words is "two hundred forty-three billion, six hundred thirty million, one hundred thousand, nine hundred twenty-one".