243086921 has 16 divisors (see below), whose sum is σ = 307599360. Its totient is φ = 186587280.

The previous prime is 243086887. The next prime is 243086933. The reversal of 243086921 is 129680342.

It is not a de Polignac number, because 243086921 - 2¹⁴ = 243070537 is a prime.

It is a super-2 number, since 2×243086921² = 118182502322520482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243086951) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18401 + ... + 28718.

It is an arithmetic number, because the mean of its divisors is an integer number (19224960).

Almost surely, 2^243086921 is an apocalyptic number.

It is an amenable number.

243086921 is a deficient number, since it is larger than the sum of its proper divisors (64512439).

243086921 is a wasteful number, since it uses less digits than its factorization.

243086921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47204.

The product of its (nonzero) digits is 20736, while the sum is 35.

The square root of 243086921 is about 15591.2450112234. The cubic root of 243086921 is about 624.0995425586.

The spelling of 243086921 in words is "two hundred forty-three million, eighty-six thousand, nine hundred twenty-one".