121500550420 has 48 divisors (see below), whose sum is σ = 262172283408. Its totient is φ = 47264117760.

The previous prime is 121500550387. The next prime is 121500550433. The reversal of 121500550420 is 24055005121.

It can be written as a sum of positive squares in 8 ways, for example, as 1205339524 + 120295210896 = 34718^2 + 346836^2 .

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 1555090 + ... + 1631350.

It is an arithmetic number, because the mean of its divisors is an integer number (5461922571).

Almost surely, 2^121500550420 is an apocalyptic number.

121500550420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121500550420 is an abundant number, since it is smaller than the sum of its proper divisors (140671732988).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

121500550420 is a wasteful number, since it uses less digits than its factorization.

121500550420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78460 (or 78458 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 25.

Adding to 121500550420 its reverse (24055005121), we get a palindrome (145555555541).

The spelling of 121500550420 in words is "one hundred twenty-one billion, five hundred million, five hundred fifty thousand, four hundred twenty".