312000021 has 12 divisors (see below), whose sum is σ = 462847372. Its totient is φ = 202378176.

The previous prime is 312000019. The next prime is 312000023. The reversal of 312000021 is 120000213.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (312000019) and next prime (312000023).

It can be written as a sum of positive squares in 2 ways, for example, as 165251025 + 146748996 = 12855^2 + 12114^2 .

It is not a de Polignac number, because 312000021 - 2¹ = 312000019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 311999967 and 312000012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (312000023) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 468136 + ... + 468801.

Almost surely, 2^312000021 is an apocalyptic number.

It is an amenable number.

312000021 is a deficient number, since it is larger than the sum of its proper divisors (150847351).

312000021 is a wasteful number, since it uses less digits than its factorization.

312000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 936980 (or 936977 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 312000021 is about 17663.5223271011. The cubic root of 312000021 is about 678.2423038198.

Adding to 312000021 its reverse (120000213), we get a palindrome (432000234).

It can be divided in two parts, 3 and 12000021, that multiplied together give a palindrome (36000063).

The spelling of 312000021 in words is "three hundred twelve million, twenty-one", and thus it is an aban number.