1221314243220 has 168 divisors, whose sum is σ = 3949311726024. Its totient is φ = 316881393408.

The previous prime is 1221314243159. The next prime is 1221314243263. The reversal of 1221314243220 is 223424131221.

1221314243220 is a `hidden beast` number, since 1 + 2 + 2 + 1 + 314 + 24 + 322 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 79395459984 + 1141918783236 = 281772^2 + 1068606^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 592519 + ... + 1671438.

It is an arithmetic number, because the mean of its divisors is an integer number (23507807893).

Almost surely, 2^{1221314243220} is an apocalyptic number.

1221314243220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221314243220 is an abundant number, since it is smaller than the sum of its proper divisors (2727997482804).

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

1221314243220 is a wasteful number, since it uses less digits than its factorization.

1221314243220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2264021 (or 2264004 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

Adding to 1221314243220 its reverse (223424131221), we get a palindrome (1444738374441).

The spelling of 1221314243220 in words is "one trillion, two hundred twenty-one billion, three hundred fourteen million, two hundred forty-three thousand, two hundred twenty".