212105520 has 320 divisors, whose sum is σ = 814233600. Its totient is φ = 50319360.

The previous prime is 212105519. The next prime is 212105527. The reversal of 212105520 is 25501212.

It is a super-2 number, since 2×212105520² = 89977503228940800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 212105493 and 212105502.

It is not an unprimeable number, because it can be changed into a prime (212105527) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1876984 + ... + 1877096.

It is an arithmetic number, because the mean of its divisors is an integer number (2544480).

Almost surely, 2^212105520 is an apocalyptic number.

212105520 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 212105520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (407116800).

212105520 is an abundant number, since it is smaller than the sum of its proper divisors (602128080).

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

212105520 is a wasteful number, since it uses less digits than its factorization.

212105520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225 (or 213 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 212105520 is about 14563.8428994548. The cubic root of 212105520 is about 596.3721082139.

Adding to 212105520 its reverse (25501212), we get a palindrome (237606732).

The spelling of 212105520 in words is "two hundred twelve million, one hundred five thousand, five hundred twenty".