9181021 has 2 divisors, whose sum is σ = 9181022. Its totient is φ = 9181020.

The previous prime is 9181019. The next prime is 9181033. The reversal of 9181021 is 1201819.

9181021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9180900 + 121 = 3030^2 + 11^2 .

It is a cyclic number.

It is not a de Polignac number, because 9181021 - 2¹ = 9181019 is a prime.

It is a super-2 number, since 2×9181021² = 168582293204882, which contains 22 as substring.

Together with 9181019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 9180983 and 9181001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9181321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4590510 + 4590511.

It is an arithmetic number, because the mean of its divisors is an integer number (4590511).

Almost surely, 2^9181021 is an apocalyptic number.

It is an amenable number.

9181021 is a deficient number, since it is larger than the sum of its proper divisors (1).

9181021 is an equidigital number, since it uses as much as digits as its factorization.

9181021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 22.

The square root of 9181021 is about 3030.0199669309. The cubic root of 9181021 is about 209.3937237581.

The spelling of 9181021 in words is "nine million, one hundred eighty-one thousand, twenty-one".