213240656 has 40 divisors (see below), whose sum is σ = 439407144. Its totient is φ = 99901440.

The previous prime is 213240653. The next prime is 213240679. The reversal of 213240656 is 656042312.

213240656 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 156750400 + 56490256 = 12520^2 + 7516^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213240653) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 63926 + ... + 67178.

Almost surely, 2^213240656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 213240656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (219703572).

213240656 is an abundant number, since it is smaller than the sum of its proper divisors (226166488).

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

213240656 is a wasteful number, since it uses less digits than its factorization.

213240656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3519 (or 3513 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 213240656 is about 14602.7619305390. The cubic root of 213240656 is about 597.4340943746.

Adding to 213240656 its reverse (656042312), we get a palindrome (869282968).

The spelling of 213240656 in words is "two hundred thirteen million, two hundred forty thousand, six hundred fifty-six".