121220520309 has 24 divisors (see below), whose sum is σ = 200207750912. Its totient is φ = 69235054560.

The previous prime is 121220520307. The next prime is 121220520349. The reversal of 121220520309 is 903025022121.

It is a happy number.

121220520309 is a `hidden beast` number, since 12 + 122 + 0 + 520 + 3 + 0 + 9 = 666.

It is not a de Polignac number, because 121220520309 - 2¹ = 121220520307 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121220520301) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 339277 + ... + 597954.

Almost surely, 2^121220520309 is an apocalyptic number.

It is an amenable number.

121220520309 is a deficient number, since it is larger than the sum of its proper divisors (78987230603).

121220520309 is a wasteful number, since it uses less digits than its factorization.

121220520309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 939297 (or 939294 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The spelling of 121220520309 in words is "one hundred twenty-one billion, two hundred twenty million, five hundred twenty thousand, three hundred nine".