1221021021200 has 30 divisors (see below), whose sum is σ = 2933503004394. Its totient is φ = 488408408320.

The previous prime is 1221021021193. The next prime is 1221021021221. The reversal of 1221021021200 is 21201201221.

It can be written as a sum of positive squares in 3 ways, for example, as 346840900624 + 874180120576 = 588932^2 + 934976^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1526275877 + ... + 1526276676.

Almost surely, 2^{1221021021200} is an apocalyptic number.

1221021021200 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221021021200 is an abundant number, since it is smaller than the sum of its proper divisors (1712481983194).

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

1221021021200 is a wasteful number, since it uses less digits than its factorization.

1221021021200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3052552571 (or 3052552560 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 1221021021200 its reverse (21201201221), we get a palindrome (1242222222421).

The spelling of 1221021021200 in words is "one trillion, two hundred twenty-one billion, twenty-one million, twenty-one thousand, two hundred".