121215125105 has 16 divisors (see below), whose sum is σ = 150084506880. Its totient is φ = 93930404352.

The previous prime is 121215125081. The next prime is 121215125107. The reversal of 121215125105 is 501521512121.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121215125105 is a prime.

It is a super-2 number, since 2×121215125105² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (121215125107) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2636015 + ... + 2681604.

It is an arithmetic number, because the mean of its divisors is an integer number (9380281680).

Almost surely, 2^121215125105 is an apocalyptic number.

It is an amenable number.

121215125105 is a deficient number, since it is larger than the sum of its proper divisors (28869381775).

121215125105 is an equidigital number, since it uses as much as digits as its factorization.

121215125105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5317768.

The product of its (nonzero) digits is 1000, while the sum is 26.

Adding to 121215125105 its reverse (501521512121), we get a palindrome (622736637226).

The spelling of 121215125105 in words is "one hundred twenty-one billion, two hundred fifteen million, one hundred twenty-five thousand, one hundred five".