1225578816 has 448 divisors, whose sum is σ = 4595896320. Its totient is φ = 311040000.

The previous prime is 1225578799. The next prime is 1225578817. The reversal of 1225578816 is 6188755221.

1225578816 is a `hidden beast` number, since 1 + 2 + 2 + 557 + 88 + 16 = 666.

It is a tau number, because it is divible by the number of its divisors (448).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1225578817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8116341 + ... + 8116491.

Almost surely, 2^1225578816 is an apocalyptic number.

1225578816 is a gapful number since it is divisible by the number (16) 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 1225578816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2297948160).

1225578816 is an abundant number, since it is smaller than the sum of its proper divisors (3370317504).

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

1225578816 is a wasteful number, since it uses less digits than its factorization.

1225578816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251 (or 235 counting only the distinct ones).

The product of its digits is 268800, while the sum is 45.

The square root of 1225578816 is about 35008.2678234728. The cubic root of 1225578816 is about 1070.1559780766.

The spelling of 1225578816 in words is "one billion, two hundred twenty-five million, five hundred seventy-eight thousand, eight hundred sixteen".