204240100121 has 2 divisors, whose sum is σ = 204240100122. Its totient is φ = 204240100120.

The previous prime is 204240100081. The next prime is 204240100151. The reversal of 204240100121 is 121001042402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 166574994496 + 37665105625 = 408136^2 + 194075^2 .

It is a cyclic number.

It is not a de Polignac number, because 204240100121 - 2²² = 204235905817 is a prime.

It is a super-2 number, since 2×204240100121² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 204240100121.

It is not a weakly prime, because it can be changed into another prime (204240100151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102120050060 + 102120050061.

It is an arithmetic number, because the mean of its divisors is an integer number (102120050061).

Almost surely, 2^204240100121 is an apocalyptic number.

It is an amenable number.

204240100121 is a deficient number, since it is larger than the sum of its proper divisors (1).

204240100121 is an equidigital number, since it uses as much as digits as its factorization.

204240100121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 204240100121 its reverse (121001042402), we get a palindrome (325241142523).

The spelling of 204240100121 in words is "two hundred four billion, two hundred forty million, one hundred thousand, one hundred twenty-one".