213309840 has 80 divisors (see below), whose sum is σ = 664082496. Its totient is φ = 56640000.

The previous prime is 213309793. The next prime is 213309841. The reversal of 213309840 is 48903312.

213309840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 213309798 and 213309807.

It is not an unprimeable number, because it can be changed into a prime (213309841) 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, 58470 + ... + 62010.

Almost surely, 2^213309840 is an apocalyptic number.

213309840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 213309840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (332041248).

213309840 is an abundant number, since it is smaller than the sum of its proper divisors (450772656).

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

213309840 is a wasteful number, since it uses less digits than its factorization.

213309840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3808 (or 3802 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 213309840 is about 14605.1306053729. The cubic root of 213309840 is about 597.4986980825.

The spelling of 213309840 in words is "two hundred thirteen million, three hundred nine thousand, eight hundred forty".