1225521800 has 24 divisors (see below), whose sum is σ = 2849338650. Its totient is φ = 490208640.

The previous prime is 1225521797. The next prime is 1225521833. The reversal of 1225521800 is 81255221.

It can be written as a sum of positive squares in 3 ways, for example, as 995150116 + 230371684 = 31546^2 + 15178^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1225521800.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3063605 + ... + 3064004.

Almost surely, 2^1225521800 is an apocalyptic number.

1225521800 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1225521800 is an abundant number, since it is smaller than the sum of its proper divisors (1623816850).

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

1225521800 is a wasteful number, since it uses less digits than its factorization.

1225521800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6127625 (or 6127616 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 26.

The square root of 1225521800 is about 35007.4534920779. The cubic root of 1225521800 is about 1070.1393826637.

The spelling of 1225521800 in words is "one billion, two hundred twenty-five million, five hundred twenty-one thousand, eight hundred".