212431021 has 4 divisors (see below), whose sum is σ = 231742944. Its totient is φ = 193119100.

The previous prime is 212431019. The next prime is 212431027. The reversal of 212431021 is 120134212.

212431021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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.

It is a cyclic number.

It is not a de Polignac number, because 212431021 - 2¹ = 212431019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212430986 and 212431004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212431027) 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, 9655945 + ... + 9655966.

It is an arithmetic number, because the mean of its divisors is an integer number (57935736).

Almost surely, 2^212431021 is an apocalyptic number.

It is an amenable number.

212431021 is a deficient number, since it is larger than the sum of its proper divisors (19311923).

212431021 is a wasteful number, since it uses less digits than its factorization.

212431021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19311922.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 212431021 is about 14575.0135848993. The cubic root of 212431021 is about 596.6770201311.

Adding to 212431021 its reverse (120134212), we get a palindrome (332565233).

The spelling of 212431021 in words is "two hundred twelve million, four hundred thirty-one thousand, twenty-one".