1221001221200 has 60 divisors (see below), whose sum is σ = 2933572767228. Its totient is φ = 488380953600.

The previous prime is 1221001221197. The next prime is 1221001221203. The reversal of 1221001221200 is 21221001221.

It is an interprime number because it is at equal distance from previous prime (1221001221197) and next prime (1221001221203).

It can be written as a sum of positive squares in 6 ways, for example, as 3121233424 + 1217879987776 = 55868^2 + 1103576^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221001221203) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13988894 + ... + 14075906.

Almost surely, 2^{1221001221200} is an apocalyptic number.

1221001221200 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221001221200 is an abundant number, since it is smaller than the sum of its proper divisors (1712571546028).

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

1221001221200 is a wasteful number, since it uses less digits than its factorization.

1221001221200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122112 (or 122101 counting only the distinct ones).

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

Adding to 1221001221200 its reverse (21221001221), we get a palindrome (1242222222421).

The spelling of 1221001221200 in words is "one trillion, two hundred twenty-one billion, one million, two hundred twenty-one thousand, two hundred".