211221040 has 40 divisors (see below), whose sum is σ = 499151088. Its totient is φ = 83101440.

The previous prime is 211221037. The next prime is 211221061. The reversal of 211221040 is 40122112.

It is a happy number.

211221040 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×211221040² = 89228655477363200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 211221040.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16762 + ... + 26521.

Almost surely, 2^211221040 is an apocalyptic number.

211221040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

211221040 is an abundant number, since it is smaller than the sum of its proper divisors (287930048).

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

211221040 is a wasteful number, since it uses less digits than its factorization.

211221040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43357 (or 43351 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 211221040 is about 14533.4455653159. The cubic root of 211221040 is about 595.5419960734.

Adding to 211221040 its reverse (40122112), we get a palindrome (251343152).

The spelling of 211221040 in words is "two hundred eleven million, two hundred twenty-one thousand, forty".