1221554254400 has 84 divisors (see below), whose sum is σ = 3009924310848. Its totient is φ = 487949130240.

The previous prime is 1221554254391. The next prime is 1221554254411. The reversal of 1221554254400 is 44524551221.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 638117 + ... + 1688283.

It is an arithmetic number, because the mean of its divisors is an integer number (35832432272).

Almost surely, 2^{1221554254400} is an apocalyptic number.

1221554254400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221554254400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1504962155424).

1221554254400 is an abundant number, since it is smaller than the sum of its proper divisors (1788370056448).

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

1221554254400 is a wasteful number, since it uses less digits than its factorization.

1221554254400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1050916 (or 1050901 counting only the distinct ones).

The product of its (nonzero) digits is 64000, while the sum is 35.

The spelling of 1221554254400 in words is "one trillion, two hundred twenty-one billion, five hundred fifty-four million, two hundred fifty-four thousand, four hundred".