211564340 has 72 divisors (see below), whose sum is σ = 490582008. Its totient is φ = 76577280.

The previous prime is 211564333. The next prime is 211564349. The reversal of 211564340 is 43465112.

211564340 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 12 ways, for example, as 47416996 + 164147344 = 6886^2 + 12812^2 .

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211564349) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 178550 + ... + 179730.

It is an arithmetic number, because the mean of its divisors is an integer number (6813639).

Almost surely, 2^211564340 is an apocalyptic number.

211564340 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 211564340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (245291004).

211564340 is an abundant number, since it is smaller than the sum of its proper divisors (279017668).

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

211564340 is a wasteful number, since it uses less digits than its factorization.

211564340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1269 (or 1254 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 211564340 is about 14545.2514588095. The cubic root of 211564340 is about 595.8644685291.

The spelling of 211564340 in words is "two hundred eleven million, five hundred sixty-four thousand, three hundred forty".