307021 has 16 divisors (see below), whose sum is σ = 383040. Its totient is φ = 241920.

The previous prime is 307019. The next prime is 307031. The reversal of 307021 is 120703.

307021 = 118² + 119² + ... + 136².

It is a 4-Lehmer number, since φ(307021) divides (307021-1)⁴.

It is a cyclic number.

It is not a de Polignac number, because 307021 - 2¹ = 307019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a nialpdrome in base 13.

It is a junction number, because it is equal to n+sod(n) for n = 306992 and 307010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (307031) 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 15 ways as a sum of consecutive naturals, for example, 2661 + ... + 2773.

It is an arithmetic number, because the mean of its divisors is an integer number (23940).

2³⁰⁷⁰²¹ is an apocalyptic number.

It is an amenable number.

307021 is a deficient number, since it is larger than the sum of its proper divisors (76019).

307021 is a wasteful number, since it uses less digits than its factorization.

307021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156.

The product of its (nonzero) digits is 42, while the sum is 13.

The square root of 307021 is about 554.0947572392. The cubic root of 307021 is about 67.4615052571.

Adding to 307021 its reverse (120703), we get a palindrome (427724).

It can be divided in two parts, 30702 and 1, that added together give a palindrome (30703).

The spelling of 307021 in words is "three hundred seven thousand, twenty-one", and thus it is an iban number.