213305640 has 32 divisors (see below), whose sum is σ = 639917280. Its totient is φ = 56881472.

The previous prime is 213305633. The next prime is 213305663. The reversal of 213305640 is 46503312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 213305640.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 888654 + ... + 888893.

It is an arithmetic number, because the mean of its divisors is an integer number (19997415).

Almost surely, 2^213305640 is an apocalyptic number.

213305640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

213305640 is an abundant number, since it is smaller than the sum of its proper divisors (426611640).

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

213305640 is a wasteful number, since it uses less digits than its factorization.

213305640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1777561 (or 1777557 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 24.

The square root of 213305640 is about 14604.9868195764. The cubic root of 213305640 is about 597.4947765397.

Adding to 213305640 its reverse (46503312), we get a palindrome (259808952).

The spelling of 213305640 in words is "two hundred thirteen million, three hundred five thousand, six hundred forty".