211653640 has 64 divisors (see below), whose sum is σ = 526176000. Its totient is φ = 75978240.

The previous prime is 211653623. The next prime is 211653641. The reversal of 211653640 is 46356112.

211653640 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 211653599 and 211653608.

It is not an unprimeable number, because it can be changed into a prime (211653641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31716 + ... + 37804.

It is an arithmetic number, because the mean of its divisors is an integer number (8221500).

Almost surely, 2^211653640 is an apocalyptic number.

211653640 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 211653640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (263088000).

211653640 is an abundant number, since it is smaller than the sum of its proper divisors (314522360).

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

211653640 is a wasteful number, since it uses less digits than its factorization.

211653640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6190 (or 6186 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 211653640 is about 14548.3208653095. The cubic root of 211653640 is about 595.9482936390.

The spelling of 211653640 in words is "two hundred eleven million, six hundred fifty-three thousand, six hundred forty".