212784421 has 4 divisors (see below), whose sum is σ = 212815072. Its totient is φ = 212753772.

The previous prime is 212784413. The next prime is 212784433. The reversal of 212784421 is 124487212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 212784421 - 2³ = 212784413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212785421) 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, 616 + ... + 20638.

It is an arithmetic number, because the mean of its divisors is an integer number (53203768).

Almost surely, 2^212784421 is an apocalyptic number.

It is an amenable number.

212784421 is a deficient number, since it is larger than the sum of its proper divisors (30651).

212784421 is a wasteful number, since it uses less digits than its factorization.

212784421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30650.

The product of its digits is 7168, while the sum is 31.

The square root of 212784421 is about 14587.1320347764. The cubic root of 212784421 is about 597.0077138844.

The spelling of 212784421 in words is "two hundred twelve million, seven hundred eighty-four thousand, four hundred twenty-one".