211147220 has 24 divisors (see below), whose sum is σ = 444390408. Its totient is φ = 84272000.

The previous prime is 211147207. The next prime is 211147309. The reversal of 211147220 is 22741112.

It can be written as a sum of positive squares in 4 ways, for example, as 58920976 + 152226244 = 7676^2 + 12338^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 211147192 and 211147201.

It is a congruent number.

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, 2231 + ... + 20670.

It is an arithmetic number, because the mean of its divisors is an integer number (18516267).

Almost surely, 2^211147220 is an apocalyptic number.

211147220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

211147220 is an abundant number, since it is smaller than the sum of its proper divisors (233243188).

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

211147220 is a wasteful number, since it uses less digits than its factorization.

211147220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23371 (or 23369 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 20.

The square root of 211147220 is about 14530.9056840928. The cubic root of 211147220 is about 595.4726089948.

Adding to 211147220 its reverse (22741112), we get a palindrome (233888332).

The spelling of 211147220 in words is "two hundred eleven million, one hundred forty-seven thousand, two hundred twenty".