1221252035568 has 20 divisors (see below), whose sum is σ = 3154901092008. Its totient is φ = 407084011840.

The previous prime is 1221252035447. The next prime is 1221252035579. The reversal of 1221252035568 is 8655302521221.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12721375323 + ... + 12721375418.

Almost surely, 2^{1221252035568} is an apocalyptic number.

It is an amenable number.

1221252035568 is an abundant number, since it is smaller than the sum of its proper divisors (1933649056440).

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

1221252035568 is a wasteful number, since it uses less digits than its factorization.

1221252035568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25442750752 (or 25442750746 counting only the distinct ones).

The product of its (nonzero) digits is 288000, while the sum is 42.

Adding to 1221252035568 its reverse (8655302521221), we get a palindrome (9876554556789).

The spelling of 1221252035568 in words is "one trillion, two hundred twenty-one billion, two hundred fifty-two million, thirty-five thousand, five hundred sixty-eight".