1221443440425 has 288 divisors, whose sum is σ = 2513742547680. Its totient is φ = 562570444800.

The previous prime is 1221443440421. The next prime is 1221443440433. The reversal of 1221443440425 is 5240443441221.

1221443440425 is a `hidden beast` number, since 1 + 2 + 214 + 4 + 34 + 404 + 2 + 5 = 666.

It can be written as a sum of positive squares in 48 ways, for example, as 1189268767296 + 32174673129 = 1090536^2 + 179373^2 .

It is not a de Polignac number, because 1221443440425 - 2² = 1221443440421 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1221443440425.

It is not an unprimeable number, because it can be changed into a prime (1221443440421) by changing a digit.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 546017407 + ... + 546019643.

It is an arithmetic number, because the mean of its divisors is an integer number (8728272735).

Almost surely, 2^{1221443440425} is an apocalyptic number.

1221443440425 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1221443440425 is an abundant number, since it is smaller than the sum of its proper divisors (1292299107255).

1221443440425 is a wasteful number, since it uses less digits than its factorization.

1221443440425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2493 (or 2485 counting only the distinct ones).

The product of its (nonzero) digits is 122880, while the sum is 36.

Adding to 1221443440425 its reverse (5240443441221), we get a palindrome (6461886881646).

The spelling of 1221443440425 in words is "one trillion, two hundred twenty-one billion, four hundred forty-three million, four hundred forty thousand, four hundred twenty-five".