213742321 has 16 divisors (see below), whose sum is σ = 236373760. Its totient is φ = 192067200.

The previous prime is 213742301. The next prime is 213742327. The reversal of 213742321 is 123247312.

It is a happy number.

It is not a de Polignac number, because 213742321 - 2¹⁵ = 213709553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213742327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 73546 + ... + 76396.

It is an arithmetic number, because the mean of its divisors is an integer number (14773360).

Almost surely, 2^213742321 is an apocalyptic number.

It is an amenable number.

213742321 is a deficient number, since it is larger than the sum of its proper divisors (22631439).

213742321 is a wasteful number, since it uses less digits than its factorization.

213742321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3016.

The product of its digits is 2016, while the sum is 25.

The square root of 213742321 is about 14619.9288985959. The cubic root of 213742321 is about 597.9022306353.

Adding to 213742321 its reverse (123247312), we get a palindrome (336989633).

It can be divided in two parts, 2137423 and 21, that added together give a square (2137444 = 1462²).

The spelling of 213742321 in words is "two hundred thirteen million, seven hundred forty-two thousand, three hundred twenty-one".