212310021 has 32 divisors (see below), whose sum is σ = 353691648. Its totient is φ = 110053440.

The previous prime is 212310017. The next prime is 212310023. The reversal of 212310021 is 120013212.

It is not a de Polignac number, because 212310021 - 2² = 212310017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 212309979 and 212310006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212310023) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 171015 + ... + 172251.

It is an arithmetic number, because the mean of its divisors is an integer number (11052864).

Almost surely, 2^212310021 is an apocalyptic number.

212310021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

212310021 is a deficient number, since it is larger than the sum of its proper divisors (141381627).

212310021 is a wasteful number, since it uses less digits than its factorization.

212310021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2001.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 212310021 is about 14570.8620541133. The cubic root of 212310021 is about 596.5637102022.

Adding to 212310021 its reverse (120013212), we get a palindrome (332323233).

The spelling of 212310021 in words is "two hundred twelve million, three hundred ten thousand, twenty-one".