1221893400 has 576 divisors, whose sum is σ = 4987180800. Its totient is φ = 244823040.

The previous prime is 1221893399. The next prime is 1221893437. The reversal of 1221893400 is 43981221.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 8790531 + ... + 8790669.

It is an arithmetic number, because the mean of its divisors is an integer number (8658300).

Almost surely, 2^1221893400 is an apocalyptic number.

1221893400 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 1221893400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2493590400).

1221893400 is an abundant number, since it is smaller than the sum of its proper divisors (3765287400).

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

1221893400 is a wasteful number, since it uses less digits than its factorization.

1221893400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208 (or 192 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 1221893400 is about 34955.5918273457. The cubic root of 1221893400 is about 1069.0822188018.

The spelling of 1221893400 in words is "one billion, two hundred twenty-one million, eight hundred ninety-three thousand, four hundred".