211530440 has 64 divisors (see below), whose sum is σ = 524180160. Its totient is φ = 76184320.

The previous prime is 211530427. The next prime is 211530481. The reversal of 211530440 is 44035112.

211530440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (20).

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, 44834 + ... + 49326.

It is an arithmetic number, because the mean of its divisors is an integer number (8190315).

Almost surely, 2^211530440 is an apocalyptic number.

211530440 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 211530440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (262090080).

211530440 is an abundant number, since it is smaller than the sum of its proper divisors (312649720).

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

211530440 is a wasteful number, since it uses less digits than its factorization.

211530440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4622 (or 4618 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 211530440 is about 14544.0860833536. The cubic root of 211530440 is about 595.8326407260.

Adding to 211530440 its reverse (44035112), we get a palindrome (255565552).

The spelling of 211530440 in words is "two hundred eleven million, five hundred thirty thousand, four hundred forty".