1221020130320 has 40 divisors (see below), whose sum is σ = 2838918159960. Its totient is φ = 488400076800.

The previous prime is 1221020130301. The next prime is 1221020130329. The reversal of 1221020130320 is 230310201221.

It can be written as a sum of positive squares in 4 ways, for example, as 349739766544 + 871280363776 = 591388^2 + 933424^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (1221020130329) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8593616 + ... + 8734544.

It is an arithmetic number, because the mean of its divisors is an integer number (70972953999).

Almost surely, 2^{1221020130320} is an apocalyptic number.

1221020130320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221020130320 is an abundant number, since it is smaller than the sum of its proper divisors (1617898029640).

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

1221020130320 is a wasteful number, since it uses less digits than its factorization.

1221020130320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249243 (or 249237 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 1221020130320 its reverse (230310201221), we get a palindrome (1451330331541).

The spelling of 1221020130320 in words is "one trillion, two hundred twenty-one billion, twenty million, one hundred thirty thousand, three hundred twenty".