1221443502420 has 24 divisors (see below), whose sum is σ = 3420041806944. Its totient is φ = 325718267296.

The previous prime is 1221443502373. The next prime is 1221443502449. The reversal of 1221443502420 is 242053441221.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

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, 10178695794 + ... + 10178695913.

It is an arithmetic number, because the mean of its divisors is an integer number (142501741956).

Almost surely, 2^{1221443502420} is an apocalyptic number.

1221443502420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221443502420 is an abundant number, since it is smaller than the sum of its proper divisors (2198598304524).

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

1221443502420 is a wasteful number, since it uses less digits than its factorization.

1221443502420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20357391719 (or 20357391717 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 30.

Adding to 1221443502420 its reverse (242053441221), we get a palindrome (1463496943641).

The spelling of 1221443502420 in words is "one trillion, two hundred twenty-one billion, four hundred forty-three million, five hundred two thousand, four hundred twenty".