121040021 has 2 divisors, whose sum is σ = 121040022. Its totient is φ = 121040020.

The previous prime is 121039991. The next prime is 121040033. The reversal of 121040021 is 120040121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 90459121 + 30580900 = 9511^2 + 5530^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121040021 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 121039984 and 121040011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121040041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60520010 + 60520011.

It is an arithmetic number, because the mean of its divisors is an integer number (60520011).

Almost surely, 2^121040021 is an apocalyptic number.

It is an amenable number.

121040021 is a deficient number, since it is larger than the sum of its proper divisors (1).

121040021 is an equidigital number, since it uses as much as digits as its factorization.

121040021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 121040021 is about 11001.8189859677. The cubic root of 121040021 is about 494.6632692686.

Adding to 121040021 its reverse (120040121), we get a palindrome (241080142).

The spelling of 121040021 in words is "one hundred twenty-one million, forty thousand, twenty-one".