213778644 has 24 divisors (see below), whose sum is σ = 502168800. Its totient is φ = 70780704.

The previous prime is 213778639. The next prime is 213778651. The reversal of 213778644 is 446877312.

213778644 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 213778596 and 213778605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57994 + ... + 61569.

It is an arithmetic number, because the mean of its divisors is an integer number (20923700).

Almost surely, 2^213778644 is an apocalyptic number.

It is an amenable number.

213778644 is an abundant number, since it is smaller than the sum of its proper divisors (288390156).

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

213778644 is a wasteful number, since it uses less digits than its factorization.

213778644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119719 (or 119717 counting only the distinct ones).

The product of its digits is 225792, while the sum is 42.

The square root of 213778644 is about 14621.1710885278. The cubic root of 213778644 is about 597.9360975403.

The spelling of 213778644 in words is "two hundred thirteen million, seven hundred seventy-eight thousand, six hundred forty-four".