312216638 has 4 divisors (see below), whose sum is σ = 468324960. Its totient is φ = 156108318.

The previous prime is 312216631. The next prime is 312216643. The reversal of 312216638 is 836612213.

312216638 is digitally balanced in base 3, 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 an emirpimes, since its reverse is a distinct semiprime: 836612213 = 29 ⋅28848697.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (312216631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78054158 + ... + 78054161.

It is an arithmetic number, because the mean of its divisors is an integer number (117081240).

Almost surely, 2^312216638 is an apocalyptic number.

312216638 is a deficient number, since it is larger than the sum of its proper divisors (156108322).

312216638 is a wasteful number, since it uses less digits than its factorization.

312216638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156108321.

The product of its digits is 10368, while the sum is 32.

The square root of 312216638 is about 17669.6530243239. The cubic root of 312216638 is about 678.3992320411.

The spelling of 312216638 in words is "three hundred twelve million, two hundred sixteen thousand, six hundred thirty-eight".