213240406 has 32 divisors (see below), whose sum is σ = 342144000. Its totient is φ = 99459360.

The previous prime is 213240403. The next prime is 213240409. The reversal of 213240406 is 604042312.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (213240403) and next prime (213240409).

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 15 ways as a sum of consecutive naturals, for example, 355695 + ... + 356293.

It is an arithmetic number, because the mean of its divisors is an integer number (10692000).

Almost surely, 2^213240406 is an apocalyptic number.

213240406 is the 7806-th centered heptagonal number.

213240406 is a deficient number, since it is larger than the sum of its proper divisors (128903594).

213240406 is a wasteful number, since it uses less digits than its factorization.

213240406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 804.

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 213240406 is about 14602.7533705120. The cubic root of 213240406 is about 597.4338609004.

Adding to 213240406 its reverse (604042312), we get a palindrome (817282718).

The spelling of 213240406 in words is "two hundred thirteen million, two hundred forty thousand, four hundred six".