312636221 has 4 divisors (see below), whose sum is σ = 317935200. Its totient is φ = 307337244.

The previous prime is 312636197. The next prime is 312636229. The reversal of 312636221 is 122636213.

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 an emirpimes, since its reverse is a distinct semiprime: 122636213 = 7 ⋅17519459.

It is a cyclic number.

It is not a de Polignac number, because 312636221 - 2¹⁸ = 312374077 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 (312636229) 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, 2649401 + ... + 2649518.

It is an arithmetic number, because the mean of its divisors is an integer number (79483800).

Almost surely, 2^312636221 is an apocalyptic number.

It is an amenable number.

312636221 is a deficient number, since it is larger than the sum of its proper divisors (5298979).

312636221 is an equidigital number, since it uses as much as digits as its factorization.

312636221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5298978.

The product of its digits is 2592, while the sum is 26.

The square root of 312636221 is about 17681.5220215908. The cubic root of 312636221 is about 678.7029926735.

The spelling of 312636221 in words is "three hundred twelve million, six hundred thirty-six thousand, two hundred twenty-one".