212111409 has 8 divisors (see below), whose sum is σ = 289713312. Its totient is φ = 137958560.

The previous prime is 212111399. The next prime is 212111437. The reversal of 212111409 is 904111212.

It is a happy number.

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 212111409 - 2⁵ = 212111377 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (212111489) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 862119 + ... + 862364.

It is an arithmetic number, because the mean of its divisors is an integer number (36214164).

Almost surely, 2^212111409 is an apocalyptic number.

It is an amenable number.

212111409 is a deficient number, since it is larger than the sum of its proper divisors (77601903).

212111409 is a wasteful number, since it uses less digits than its factorization.

212111409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1724527.

The product of its (nonzero) digits is 144, while the sum is 21.

The square root of 212111409 is about 14564.0450768322. The cubic root of 212111409 is about 596.3776274838.

It can be divided in two parts, 2121 and 11409, that added together give a triangular number (13530 = T₁₆₄).

The spelling of 212111409 in words is "two hundred twelve million, one hundred eleven thousand, four hundred nine".