121821090550 has 12 divisors (see below), whose sum is σ = 226587228516. Its totient is φ = 48728436200.

The previous prime is 121821090533. The next prime is 121821090557. The reversal of 121821090550 is 55090128121.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121821090557) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1218210856 + ... + 1218210955.

It is an arithmetic number, because the mean of its divisors is an integer number (18882269043).

Almost surely, 2^121821090550 is an apocalyptic number.

121821090550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

121821090550 is a deficient number, since it is larger than the sum of its proper divisors (104766137966).

121821090550 is a wasteful number, since it uses less digits than its factorization.

121821090550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2436421823 (or 2436421818 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 34.

The spelling of 121821090550 in words is "one hundred twenty-one billion, eight hundred twenty-one million, ninety thousand, five hundred fifty".