211400640 has 168 divisors, whose sum is σ = 793351728. Its totient is φ = 51240960.

The previous prime is 211400617. The next prime is 211400641. The reversal of 211400640 is 46004112.

211400640 is a `hidden beast` number, since 21 + 1 + 4 + 0 + 0 + 640 = 666.

211400640 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 (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211400641) 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, 28344 + ... + 35016.

Almost surely, 2^211400640 is an apocalyptic number.

211400640 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 211400640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (396675864).

211400640 is an abundant number, since it is smaller than the sum of its proper divisors (581951088).

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

211400640 is a wasteful number, since it uses less digits than its factorization.

211400640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6707 (or 6694 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 211400640 is about 14539.6231037809. The cubic root of 211400640 is about 595.7107435321.

Adding to 211400640 its reverse (46004112), we get a palindrome (257404752).

The spelling of 211400640 in words is "two hundred eleven million, four hundred thousand, six hundred forty".