211641540 has 48 divisors (see below), whose sum is σ = 646470720. Its totient is φ = 51306880.

The previous prime is 211641511. The next prime is 211641541. The reversal of 211641540 is 45146112.

It is a happy number.

It is a super-3 number, since 3×211641540³ (a number of 26 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 211641540.

It is not an unprimeable number, because it can be changed into a prime (211641541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 159675 + ... + 160994.

It is an arithmetic number, because the mean of its divisors is an integer number (13468140).

Almost surely, 2^211641540 is an apocalyptic number.

211641540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

211641540 is an abundant number, since it is smaller than the sum of its proper divisors (434829180).

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

211641540 is a wasteful number, since it uses less digits than its factorization.

211641540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320692 (or 320690 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 211641540 is about 14547.9050038141. The cubic root of 211641540 is about 595.9369368586.

Adding to 211641540 its reverse (45146112), we get a palindrome (256787652).

The spelling of 211641540 in words is "two hundred eleven million, six hundred forty-one thousand, five hundred forty".