212728905 has 48 divisors (see below), whose sum is σ = 391906944. Its totient is φ = 106375680.

The previous prime is 212728897. The next prime is 212728907. The reversal of 212728905 is 509827212.

It is not a de Polignac number, because 212728905 - 2³ = 212728897 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 212728905.

It is not an unprimeable number, because it can be changed into a prime (212728907) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 372270 + ... + 372840.

It is an arithmetic number, because the mean of its divisors is an integer number (8164728).

Almost surely, 2^212728905 is an apocalyptic number.

It is an amenable number.

212728905 is a deficient number, since it is larger than the sum of its proper divisors (179178039).

212728905 is a wasteful number, since it uses less digits than its factorization.

212728905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1086 (or 1083 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 212728905 is about 14585.2290006019. The cubic root of 212728905 is about 596.9557890882.

The spelling of 212728905 in words is "two hundred twelve million, seven hundred twenty-eight thousand, nine hundred five".