243407021 has 16 divisors (see below), whose sum is σ = 287642880. Its totient is φ = 203056320.

The previous prime is 243406993. The next prime is 243407023. The reversal of 243407021 is 120704342.

It is a cyclic number.

It is not a de Polignac number, because 243407021 - 2¹⁸ = 243144877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243407023) 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, 19820 + ... + 29658.

It is an arithmetic number, because the mean of its divisors is an integer number (17977680).

Almost surely, 2^243407021 is an apocalyptic number.

It is an amenable number.

243407021 is a deficient number, since it is larger than the sum of its proper divisors (44235859).

243407021 is a wasteful number, since it uses less digits than its factorization.

243407021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10036.

The product of its (nonzero) digits is 1344, while the sum is 23.

The square root of 243407021 is about 15601.5070105423. The cubic root of 243407021 is about 624.3733631854.

The spelling of 243407021 in words is "two hundred forty-three million, four hundred seven thousand, twenty-one".