1221353646000 has 160 divisors (see below), whose sum is σ = 4044067704768. Its totient is φ = 316891699200.

The previous prime is 1221353645971. The next prime is 1221353646011. The reversal of 1221353646000 is 6463531221.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2528797 + ... + 2972796.

Almost surely, 2^{1221353646000} is an apocalyptic number.

1221353646000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221353646000 is an abundant number, since it is smaller than the sum of its proper divisors (2822714058768).

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

1221353646000 is a wasteful number, since it uses less digits than its factorization.

1221353646000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5501656 (or 5501640 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 33.

The spelling of 1221353646000 in words is "one trillion, two hundred twenty-one billion, three hundred fifty-three million, six hundred forty-six thousand".