3120021 has 6 divisors (see below), whose sum is σ = 4506710. Its totient is φ = 2080008.

The previous prime is 3120017. The next prime is 3120067. The reversal of 3120021 is 1200213.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1920996 + 1199025 = 1386^2 + 1095^2 .

It is not a de Polignac number, because 3120021 - 2² = 3120017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 346669 = 3120021 / (3 + 1 + 2 + 0 + 0 + 2 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 3119985 and 3120012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3120011) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 173326 + ... + 173343.

Almost surely, 2^3120021 is an apocalyptic number.

It is an amenable number.

3120021 is a deficient number, since it is larger than the sum of its proper divisors (1386689).

3120021 is a wasteful number, since it uses less digits than its factorization.

3120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 346675 (or 346672 counting only the distinct ones).

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

The square root of 3120021 is about 1766.3581177100. The cubic root of 3120021 is about 146.1231993203.

Adding to 3120021 its reverse (1200213), we get a palindrome (4320234).

It can be divided in two parts, 3 and 120021, that multiplied together give a palindrome (360063).

The spelling of 3120021 in words is "three million, one hundred twenty thousand, twenty-one".