1221202221000 has 64 divisors (see below), whose sum is σ = 3810150938880. Its totient is φ = 325653924800.

The previous prime is 1221202220969. The next prime is 1221202221047. The reversal of 1221202221000 is 1222021221.

It is a Harshad number since it is a multiple of its sum of digits (15).

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, 203530704 + ... + 203536703.

It is an arithmetic number, because the mean of its divisors is an integer number (59533608420).

Almost surely, 2^{1221202221000} is an apocalyptic number.

1221202221000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221202221000 is an abundant number, since it is smaller than the sum of its proper divisors (2588948717880).

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

1221202221000 is a wasteful number, since it uses less digits than its factorization.

1221202221000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407067431 (or 407067417 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 1221202221000 its reverse (1222021221), we get a palindrome (1222424242221).

The spelling of 1221202221000 in words is "one trillion, two hundred twenty-one billion, two hundred two million, two hundred twenty-one thousand".