121720550031 has 6 divisors (see below), whose sum is σ = 175818572280. Its totient is φ = 81147033348.

The previous prime is 121720550027. The next prime is 121720550057. The reversal of 121720550031 is 130055027121.

121720550031 is a `hidden beast` number, since 12 + 1 + 72 + 0 + 550 + 0 + 31 = 666.

It is not a de Polignac number, because 121720550031 - 2² = 121720550027 is a prime.

It is a super-2 number, since 2×121720550031² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 121720549977 and 121720550004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121720550071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6762252771 + ... + 6762252788.

It is an arithmetic number, because the mean of its divisors is an integer number (29303095380).

Almost surely, 2^121720550031 is an apocalyptic number.

121720550031 is a deficient number, since it is larger than the sum of its proper divisors (54098022249).

121720550031 is a wasteful number, since it uses less digits than its factorization.

121720550031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13524505565 (or 13524505562 counting only the distinct ones).

The product of its (nonzero) digits is 2100, while the sum is 27.

Adding to 121720550031 its reverse (130055027121), we get a palindrome (251775577152).

The spelling of 121720550031 in words is "one hundred twenty-one billion, seven hundred twenty million, five hundred fifty thousand, thirty-one".