1021125121 has 2 divisors, whose sum is σ = 1021125122. Its totient is φ = 1021125120.

The previous prime is 1021125101. The next prime is 1021125137. The reversal of 1021125121 is 1215211201.

It is an a-pointer prime, because the next prime (1021125137) can be obtained adding 1021125121 to its sum of digits (16).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 671846400 + 349278721 = 25920^2 + 18689^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021125121 - 2¹¹ = 1021123073 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1021125095 and 1021125104.

It is not a weakly prime, because it can be changed into another prime (1021125101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510562560 + 510562561.

It is an arithmetic number, because the mean of its divisors is an integer number (510562561).

Almost surely, 2^1021125121 is an apocalyptic number.

It is an amenable number.

1021125121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021125121 is an equidigital number, since it uses as much as digits as its factorization.

1021125121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40, while the sum is 16.

The square root of 1021125121 is about 31955.0484430864. The cubic root of 1021125121 is about 1006.9926952375.

Adding to 1021125121 its reverse (1215211201), we get a palindrome (2236336322).

The spelling of 1021125121 in words is "one billion, twenty-one million, one hundred twenty-five thousand, one hundred twenty-one".