1221443432540 has 48 divisors (see below), whose sum is σ = 2608747797600. Its totient is φ = 480251937792.

The previous prime is 1221443432527. The next prime is 1221443432557. The reversal of 1221443432540 is 452343441221.

It is a self number, because there is not a number n which added to its sum of digits gives 1221443432540.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14600912 + ... + 14684328.

It is an arithmetic number, because the mean of its divisors is an integer number (54348912450).

Almost surely, 2^{1221443432540} is an apocalyptic number.

1221443432540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221443432540 is an abundant number, since it is smaller than the sum of its proper divisors (1387304365060).

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

1221443432540 is a wasteful number, since it uses less digits than its factorization.

1221443432540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95894 (or 95892 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 35.

Adding to 1221443432540 its reverse (452343441221), we get a palindrome (1673786873761).

The spelling of 1221443432540 in words is "one trillion, two hundred twenty-one billion, four hundred forty-three million, four hundred thirty-two thousand, five hundred forty".