1221544515342 has 32 divisors (see below), whose sum is σ = 2590761700512. Its totient is φ = 382642755584.

The previous prime is 1221544515311. The next prime is 1221544515349. The reversal of 1221544515342 is 2435154451221.

It is a self number, because there is not a number n which added to its sum of digits gives 1221544515342.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221544515349) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9103323 + ... + 9236534.

It is an arithmetic number, because the mean of its divisors is an integer number (80961303141).

Almost surely, 2^{1221544515342} is an apocalyptic number.

1221544515342 is an abundant number, since it is smaller than the sum of its proper divisors (1369217185170).

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

1221544515342 is a wasteful number, since it uses less digits than its factorization.

1221544515342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18340532.

The product of its digits is 192000, while the sum is 39.

Adding to 1221544515342 its reverse (2435154451221), we get a palindrome (3656698966563).

The spelling of 1221544515342 in words is "one trillion, two hundred twenty-one billion, five hundred forty-four million, five hundred fifteen thousand, three hundred forty-two".