121220021000 has 64 divisors (see below), whose sum is σ = 305474485680. Its totient is φ = 44758156800.

The previous prime is 121220020991. The next prime is 121220021057. The reversal of 121220021000 is 120022121.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 47803396 + 121172217604 = 6914^2 + 348098^2 .

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 15 ways as a sum of consecutive naturals, for example, 4649309 + ... + 4675308.

Almost surely, 2^121220021000 is an apocalyptic number.

121220021000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121220021000 is an abundant number, since it is smaller than the sum of its proper divisors (184254464680).

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

121220021000 is a wasteful number, since it uses less digits than its factorization.

121220021000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9324651 (or 9324637 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 121220021000 its reverse (120022121), we get a palindrome (121340043121).

The spelling of 121220021000 in words is "one hundred twenty-one billion, two hundred twenty million, twenty-one thousand".