1220521213544 has 32 divisors (see below), whose sum is σ = 2304607310400. Its totient is φ = 605962684800.

The previous prime is 1220521213529. The next prime is 1220521213607. The reversal of 1220521213544 is 4453121250221.

It is a self number, because there is not a number n which added to its sum of digits gives 1220521213544.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2658887 + ... + 3083945.

It is an arithmetic number, because the mean of its divisors is an integer number (72018978450).

Almost surely, 2^{1220521213544} is an apocalyptic number.

It is an amenable number.

1220521213544 is a deficient number, since it is larger than the sum of its proper divisors (1084086096856).

1220521213544 is a wasteful number, since it uses less digits than its factorization.

1220521213544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 427593 (or 427589 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 32.

Adding to 1220521213544 its reverse (4453121250221), we get a palindrome (5673642463765).

The spelling of 1220521213544 in words is "one trillion, two hundred twenty billion, five hundred twenty-one million, two hundred thirteen thousand, five hundred forty-four".