212106405 has 32 divisors (see below), whose sum is σ = 408268800. Its totient is φ = 91858752.

The previous prime is 212106403. The next prime is 212106413. The reversal of 212106405 is 504601212.

212106405 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 212106405 - 2¹ = 212106403 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212106403) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 51165 + ... + 55154.

It is an arithmetic number, because the mean of its divisors is an integer number (12758400).

Almost surely, 2^212106405 is an apocalyptic number.

It is an amenable number.

212106405 is a deficient number, since it is larger than the sum of its proper divisors (196162395).

212106405 is a wasteful number, since it uses less digits than its factorization.

212106405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106353.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 212106405 is about 14563.8732828874. The cubic root of 212106405 is about 596.3729376573.

Adding to 212106405 its reverse (504601212), we get a palindrome (716707617).

The spelling of 212106405 in words is "two hundred twelve million, one hundred six thousand, four hundred five".