1221051300 has 144 divisors (see below), whose sum is σ = 4062156672. Its totient is φ = 277401600.

The previous prime is 1221051289. The next prime is 1221051313. The reversal of 1221051300 is 31501221.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1221051300.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 361620 + ... + 364980.

Almost surely, 2^1221051300 is an apocalyptic number.

1221051300 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221051300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2031078336).

1221051300 is an abundant number, since it is smaller than the sum of its proper divisors (2841105372).

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

1221051300 is a wasteful number, since it uses less digits than its factorization.

1221051300 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3558 (or 3551 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 1221051300 is about 34943.5444681847. The cubic root of 1221051300 is about 1068.8365669766.

Adding to 1221051300 its reverse (31501221), we get a palindrome (1252552521).

The spelling of 1221051300 in words is "one billion, two hundred twenty-one million, fifty-one thousand, three hundred".