121540220417 has 32 divisors (see below), whose sum is σ = 152714225664. Its totient is φ = 93969014400.

The previous prime is 121540220387. The next prime is 121540220423. The reversal of 121540220417 is 714022045121.

It is a cyclic number.

It is not a de Polignac number, because 121540220417 - 2³⁰ = 120466478593 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121540220417.

It is not an unprimeable number, because it can be changed into a prime (121540223417) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7334213 + ... + 7350765.

It is an arithmetic number, because the mean of its divisors is an integer number (4772319552).

Almost surely, 2^121540220417 is an apocalyptic number.

It is an amenable number.

121540220417 is a deficient number, since it is larger than the sum of its proper divisors (31174005247).

121540220417 is a wasteful number, since it uses less digits than its factorization.

121540220417 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17309.

The product of its (nonzero) digits is 4480, while the sum is 29.

Adding to 121540220417 its reverse (714022045121), we get a palindrome (835562265538).

The spelling of 121540220417 in words is "one hundred twenty-one billion, five hundred forty million, two hundred twenty thousand, four hundred seventeen".