1221400330400 has 36 divisors (see below), whose sum is σ = 2981743558542. Its totient is φ = 488560131840.

The previous prime is 1221400330387. The next prime is 1221400330427. The reversal of 1221400330400 is 40330041221.

It can be written as a sum of positive squares in 3 ways, for example, as 513991492624 + 707408837776 = 716932^2 + 841076^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 763374407 + ... + 763376006.

Almost surely, 2^{1221400330400} is an apocalyptic number.

1221400330400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221400330400 is an abundant number, since it is smaller than the sum of its proper divisors (1760343228142).

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

1221400330400 is a wasteful number, since it uses less digits than its factorization.

1221400330400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1526750433 (or 1526750420 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 1221400330400 its reverse (40330041221), we get a palindrome (1261730371621).

The spelling of 1221400330400 in words is "one trillion, two hundred twenty-one billion, four hundred million, three hundred thirty thousand, four hundred".