312000721 has 4 divisors (see below), whose sum is σ = 312189552. Its totient is φ = 311811892.

The previous prime is 312000683. The next prime is 312000737. The reversal of 312000721 is 127000213.

It is a happy number.

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: 127000213 = 4073 ⋅31181.

It is a cyclic number.

It is not a de Polignac number, because 312000721 - 2¹⁹ = 311476433 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 312000695 and 312000704.

It is not an unprimeable number, because it can be changed into a prime (312000751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 91915 + ... + 95248.

It is an arithmetic number, because the mean of its divisors is an integer number (78047388).

Almost surely, 2^312000721 is an apocalyptic number.

It is an amenable number.

312000721 is a deficient number, since it is larger than the sum of its proper divisors (188831).

312000721 is a wasteful number, since it uses less digits than its factorization.

312000721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188830.

The product of its (nonzero) digits is 84, while the sum is 16.

The square root of 312000721 is about 17663.5421419374. The cubic root of 312000721 is about 678.2428110519.

Adding to 312000721 its reverse (127000213), we get a palindrome (439000934).

The spelling of 312000721 in words is "three hundred twelve million, seven hundred twenty-one", and thus it is an aban number.