212105540 has 48 divisors (see below), whose sum is σ = 472469760. Its totient is φ = 79812480.

The previous prime is 212105539. The next prime is 212105557. The reversal of 212105540 is 45501212.

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

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24281 + ... + 31839.

It is an arithmetic number, because the mean of its divisors is an integer number (9843120).

Almost surely, 2^212105540 is an apocalyptic number.

212105540 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 212105540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (236234880).

212105540 is an abundant number, since it is smaller than the sum of its proper divisors (260364220).

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

212105540 is a wasteful number, since it uses less digits than its factorization.

212105540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7652 (or 7650 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 212105540 is about 14563.8435860867. The cubic root of 212105540 is about 596.3721269584.

Adding to 212105540 its reverse (45501212), we get a palindrome (257606752).

The spelling of 212105540 in words is "two hundred twelve million, one hundred five thousand, five hundred forty".