212809231 has 4 divisors (see below), whose sum is σ = 212946264. Its totient is φ = 212672200.

The previous prime is 212809217. The next prime is 212809241. The reversal of 212809231 is 132908212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 212809231 - 2¹¹ = 212807183 is a prime.

It is a super-2 number, since 2×212809231² = 90575537597622722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 212809231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212809211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66160 + ... + 69301.

It is an arithmetic number, because the mean of its divisors is an integer number (53236566).

Almost surely, 2^212809231 is an apocalyptic number.

212809231 is a deficient number, since it is larger than the sum of its proper divisors (137033).

212809231 is a wasteful number, since it uses less digits than its factorization.

212809231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137032.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 212809231 is about 14587.9824170445. The cubic root of 212809231 is about 597.0309160619.

The spelling of 212809231 in words is "two hundred twelve million, eight hundred nine thousand, two hundred thirty-one".