243668277937721 has 36 divisors (see below), whose sum is σ = 306951739216704. Its totient is φ = 192780078472800.

The previous prime is 243668277937681. The next prime is 243668277937723. The reversal of 243668277937721 is 127739772866342.

It is not a de Polignac number, because 243668277937721 - 2¹⁸ = 243668277675577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243668277937723) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 128832716 + ... + 130710386.

It is an arithmetic number, because the mean of its divisors is an integer number (8526437200464).

Almost surely, 2^{243668277937721} is an apocalyptic number.

It is an amenable number.

243668277937721 is a deficient number, since it is larger than the sum of its proper divisors (63283461278983).

243668277937721 is a wasteful number, since it uses less digits than its factorization.

243668277937721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1893382 (or 1893362 counting only the distinct ones).

The product of its digits is 1792336896, while the sum is 74.

The spelling of 243668277937721 in words is "two hundred forty-three trillion, six hundred sixty-eight billion, two hundred seventy-seven million, nine hundred thirty-seven thousand, seven hundred twenty-one".