213240405 has 48 divisors (see below), whose sum is σ = 398974464. Its totient is φ = 96969600.

The previous prime is 213240403. The next prime is 213240409. The reversal of 213240405 is 504042312.

It is not a de Polignac number, because 213240405 - 2¹ = 213240403 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213240403) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 163255 + ... + 164555.

It is an arithmetic number, because the mean of its divisors is an integer number (8311968).

Almost surely, 2^213240405 is an apocalyptic number.

It is an amenable number.

213240405 is a deficient number, since it is larger than the sum of its proper divisors (185734059).

213240405 is a wasteful number, since it uses less digits than its factorization.

213240405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1546 (or 1539 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 213240405 is about 14602.7533362719. The cubic root of 213240405 is about 597.4338599665.

Adding to 213240405 its reverse (504042312), we get a palindrome (717282717).

The spelling of 213240405 in words is "two hundred thirteen million, two hundred forty thousand, four hundred five".