121238921772 has 144 divisors (see below), whose sum is σ = 319903234560. Its totient is φ = 40148561088.

The previous prime is 121238921693. The next prime is 121238921789. The reversal of 121238921772 is 277129832121.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 168621229 + ... + 168621947.

It is an arithmetic number, because the mean of its divisors is an integer number (2221550240).

Almost surely, 2^121238921772 is an apocalyptic number.

121238921772 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121238921772, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (159951617280).

121238921772 is an abundant number, since it is smaller than the sum of its proper divisors (198664312788).

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

121238921772 is a wasteful number, since it uses less digits than its factorization.

121238921772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1634 (or 1620 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The spelling of 121238921772 in words is "one hundred twenty-one billion, two hundred thirty-eight million, nine hundred twenty-one thousand, seven hundred seventy-two".