312122021 has 4 divisors (see below), whose sum is σ = 315629100. Its totient is φ = 308614944.

The previous prime is 312122009. The next prime is 312122051. The reversal of 312122021 is 120221213.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 105165025 + 206956996 = 10255^2 + 14386^2 .

It is a cyclic number.

It is not a de Polignac number, because 312122021 - 2¹⁴ = 312105637 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 312121987 and 312122005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (312122051) 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, 1753406 + ... + 1753583.

It is an arithmetic number, because the mean of its divisors is an integer number (78907275).

Almost surely, 2^312122021 is an apocalyptic number.

It is an amenable number.

312122021 is a deficient number, since it is larger than the sum of its proper divisors (3507079).

312122021 is an equidigital number, since it uses as much as digits as its factorization.

312122021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3507078.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 312122021 is about 17666.9754344087. The cubic root of 312122021 is about 678.3306956709.

Adding to 312122021 its reverse (120221213), we get a palindrome (432343234).

It can be divided in two parts, 31212 and 2021, that added together give a palindrome (33233).

The spelling of 312122021 in words is "three hundred twelve million, one hundred twenty-two thousand, twenty-one".