109121021 has 2 divisors, whose sum is σ = 109121022. Its totient is φ = 109121020.

The previous prime is 109121017. The next prime is 109121027. The reversal of 109121021 is 120121901.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 106605625 + 2515396 = 10325^2 + 1586^2 .

It is an emirp because it is prime and its reverse (120121901) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 109121021 - 2² = 109121017 is a prime.

It is a super-3 number, since 3×109121021³ (a number of 25 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (109121027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54560510 + 54560511.

It is an arithmetic number, because the mean of its divisors is an integer number (54560511).

Almost surely, 2^109121021 is an apocalyptic number.

It is an amenable number.

109121021 is a deficient number, since it is larger than the sum of its proper divisors (1).

109121021 is an equidigital number, since it uses as much as digits as its factorization.

109121021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 17.

The square root of 109121021 is about 10446.1007557844. The cubic root of 109121021 is about 477.8623416790.

Adding to 109121021 its reverse (120121901), we get a palindrome (229242922).

The spelling of 109121021 in words is "one hundred nine million, one hundred twenty-one thousand, twenty-one".