212261405 has 8 divisors (see below), whose sum is σ = 269696952. Its totient is φ = 159820288.

The previous prime is 212261389. The next prime is 212261531. The reversal of 212261405 is 504162212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 68525284 + 143736121 = 8278^2 + 11989^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 212261405 - 2⁴ = 212261389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1248512 + ... + 1248681.

It is an arithmetic number, because the mean of its divisors is an integer number (33712119).

Almost surely, 2^212261405 is an apocalyptic number.

It is an amenable number.

212261405 is a deficient number, since it is larger than the sum of its proper divisors (57435547).

212261405 is a wasteful number, since it uses less digits than its factorization.

212261405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2497215.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 212261405 is about 14569.1936976622. The cubic root of 212261405 is about 596.5181718346.

The spelling of 212261405 in words is "two hundred twelve million, two hundred sixty-one thousand, four hundred five".