213021840 has 80 divisors (see below), whose sum is σ = 672867648. Its totient is φ = 55730688.

The previous prime is 213021833. The next prime is 213021859. The reversal of 213021840 is 48120312.

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

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4347 + ... + 21093.

Almost surely, 2^213021840 is an apocalyptic number.

213021840 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 213021840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (336433824).

213021840 is an abundant number, since it is smaller than the sum of its proper divisors (459845808).

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

213021840 is a wasteful number, since it uses less digits than its factorization.

213021840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16816 (or 16810 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 213021840 is about 14595.2677262187. The cubic root of 213021840 is about 597.2296729443.

The spelling of 213021840 in words is "two hundred thirteen million, twenty-one thousand, eight hundred forty".