243121680 has 60 divisors (see below), whose sum is σ = 816486060. Its totient is φ = 64832256.

The previous prime is 243121667. The next prime is 243121687. The reversal of 243121680 is 86121342.

It can be written as a sum of positive squares in 2 ways, for example, as 151880976 + 91240704 = 12324^2 + 9552^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is not an unprimeable number, because it can be changed into a prime (243121687) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 168115 + ... + 169554.

It is an arithmetic number, because the mean of its divisors is an integer number (13608101).

Almost surely, 2^243121680 is an apocalyptic number.

243121680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

243121680 is an abundant number, since it is smaller than the sum of its proper divisors (573364380).

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

243121680 is a wasteful number, since it uses less digits than its factorization.

243121680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 337688 (or 337679 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 243121680 is about 15592.3596674782. The cubic root of 243121680 is about 624.1292878064.

The spelling of 243121680 in words is "two hundred forty-three million, one hundred twenty-one thousand, six hundred eighty".