212505405 has 48 divisors (see below), whose sum is σ = 416364480. Its totient is φ = 92026368.

The previous prime is 212505401. The next prime is 212505431. The reversal of 212505405 is 504505212.

It is a happy number.

It is not a de Polignac number, because 212505405 - 2² = 212505401 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212505401) 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, 6357 + ... + 21573.

It is an arithmetic number, because the mean of its divisors is an integer number (8674260).

Almost surely, 2^212505405 is an apocalyptic number.

It is an amenable number.

212505405 is a deficient number, since it is larger than the sum of its proper divisors (203859075).

212505405 is a wasteful number, since it uses less digits than its factorization.

212505405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15258 (or 15251 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 24.

The square root of 212505405 is about 14577.5651259049. The cubic root of 212505405 is about 596.7466553534.

The spelling of 212505405 in words is "two hundred twelve million, five hundred five thousand, four hundred five".