1221142530 has 64 divisors (see below), whose sum is σ = 2986201728. Its totient is φ = 319503360.

The previous prime is 1221142511. The next prime is 1221142547. The reversal of 1221142530 is 352411221.

It is a junction number, because it is equal to n+sod(n) for n = 1221142497 and 1221142506.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1249402 + ... + 1250378.

It is an arithmetic number, because the mean of its divisors is an integer number (46659402).

Almost surely, 2^1221142530 is an apocalyptic number.

1221142530 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221142530, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1493100864).

1221142530 is an abundant number, since it is smaller than the sum of its proper divisors (1765059198).

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

1221142530 is a wasteful number, since it uses less digits than its factorization.

1221142530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1731.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 1221142530 is about 34944.8498351331. The cubic root of 1221142530 is about 1068.8631854410.

Adding to 1221142530 its reverse (352411221), we get a palindrome (1573553751).

The spelling of 1221142530 in words is "one billion, two hundred twenty-one million, one hundred forty-two thousand, five hundred thirty".