1221543100452 has 48 divisors (see below), whose sum is σ = 2892989195712. Its totient is φ = 401123274240.

The previous prime is 1221543100441. The next prime is 1221543100493. The reversal of 1221543100452 is 2540013451221.

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, 2620633 + ... + 3051360.

It is an arithmetic number, because the mean of its divisors is an integer number (60270608244).

Almost surely, 2^{1221543100452} is an apocalyptic number.

1221543100452 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1221543100452 is an abundant number, since it is smaller than the sum of its proper divisors (1671446095260).

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

1221543100452 is a wasteful number, since it uses less digits than its factorization.

1221543100452 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5672268 (or 5672266 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 30.

Adding to 1221543100452 its reverse (2540013451221), we get a palindrome (3761556551673).

The spelling of 1221543100452 in words is "one trillion, two hundred twenty-one billion, five hundred forty-three million, one hundred thousand, four hundred fifty-two".