1221290214400 has 99 divisors (see below), whose sum is σ = 3027759186549. Its totient is φ = 488445358080.

The previous prime is 1221290214377. The next prime is 1221290214449. The reversal of 1221290214400 is 44120921221.

The square root of 1221290214400 is 1105120.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 439664477184 + 781625737216 = 663072^2 + 884096^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 176815747 + ... + 176822653.

Almost surely, 2^{1221290214400} is an apocalyptic number.

1221290214400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221290214400 is the 1105120-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221290214400

1221290214400 is an abundant number, since it is smaller than the sum of its proper divisors (1806468972149).

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

1221290214400 is an frugal number, since it uses more digits than its factorization.

1221290214400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13844 (or 6914 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The spelling of 1221290214400 in words is "one trillion, two hundred twenty-one billion, two hundred ninety million, two hundred fourteen thousand, four hundred".