1221925824 has 280 divisors, whose sum is σ = 4185724928. Its totient is φ = 345254400.

The previous prime is 1221925823. The next prime is 1221925843. The reversal of 1221925824 is 4285291221.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221925823) by changing a digit.

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 39 ways as a sum of consecutive naturals, for example, 5479377 + ... + 5479599.

Almost surely, 2^1221925824 is an apocalyptic number.

1221925824 is a gapful number since it is divisible by the number (14) 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 1221925824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2092862464).

1221925824 is an abundant number, since it is smaller than the sum of its proper divisors (2963799104).

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

1221925824 is a wasteful number, since it uses less digits than its factorization.

1221925824 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405 (or 386 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 1221925824 is about 34956.0556127261. The cubic root of 1221925824 is about 1069.0916750591.

The spelling of 1221925824 in words is "one billion, two hundred twenty-one million, nine hundred twenty-five thousand, eight hundred twenty-four".