1205140121 has 2 divisors, whose sum is σ = 1205140122. Its totient is φ = 1205140120.

The previous prime is 1205140109. The next prime is 1205140127. The reversal of 1205140121 is 1210415021.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1180884496 + 24255625 = 34364^2 + 4925^2 .

It is a cyclic number.

It is not a de Polignac number, because 1205140121 - 2³⁰ = 131398297 is a prime.

It is a super-2 number, since 2×1205140121² = 2904725422487789282, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1205140121.

It is not a weakly prime, because it can be changed into another prime (1205140127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 602570060 + 602570061.

It is an arithmetic number, because the mean of its divisors is an integer number (602570061).

Almost surely, 2^1205140121 is an apocalyptic number.

It is an amenable number.

1205140121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1205140121 is an equidigital number, since it uses as much as digits as its factorization.

1205140121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 80, while the sum is 17.

The square root of 1205140121 is about 34715.1281288144. The cubic root of 1205140121 is about 1064.1736839469.

Adding to 1205140121 its reverse (1210415021), we get a palindrome (2415555142).

The spelling of 1205140121 in words is "one billion, two hundred five million, one hundred forty thousand, one hundred twenty-one".