213918644 has 12 divisors (see below), whose sum is σ = 394060800. Its totient is φ = 101329848.

The previous prime is 213918629. The next prime is 213918647. The reversal of 213918644 is 446819312.

It is a super-2 number, since 2×213918644² = 91522372501597472, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a junction number, because it is equal to n+sod(n) for n = 213918598 and 213918607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213918647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1407284 + ... + 1407435.

It is an arithmetic number, because the mean of its divisors is an integer number (32838400).

Almost surely, 2^213918644 is an apocalyptic number.

It is an amenable number.

213918644 is a deficient number, since it is larger than the sum of its proper divisors (180142156).

213918644 is a wasteful number, since it uses less digits than its factorization.

213918644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2814742 (or 2814740 counting only the distinct ones).

The product of its digits is 41472, while the sum is 38.

The square root of 213918644 is about 14625.9578831610. The cubic root of 213918644 is about 598.0665951196.

The spelling of 213918644 in words is "two hundred thirteen million, nine hundred eighteen thousand, six hundred forty-four".