1221240300 has 144 divisors (see below), whose sum is σ = 4048907520. Its totient is φ = 278403840.

The previous prime is 1221240277. The next prime is 1221240301. The reversal of 1221240300 is 30421221.

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 1221240300.

It is not an unprimeable number, because it can be changed into a prime (1221240301) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1421271 + ... + 1422129.

Almost surely, 2^1221240300 is an apocalyptic number.

1221240300 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 1221240300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2024453760).

1221240300 is an abundant number, since it is smaller than the sum of its proper divisors (2827667220).

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

1221240300 is a wasteful number, since it uses less digits than its factorization.

1221240300 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1560 (or 1553 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 1221240300 is about 34946.2487257216. The cubic root of 1221240300 is about 1068.8917106301.

Adding to 1221240300 its reverse (30421221), we get a palindrome (1251661521).

The spelling of 1221240300 in words is "one billion, two hundred twenty-one million, two hundred forty thousand, three hundred".