1225556780 has 24 divisors (see below), whose sum is σ = 2941336608. Its totient is φ = 420190848.

The previous prime is 1225556749. The next prime is 1225556851. The reversal of 1225556780 is 876555221.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 4376849 + ... + 4377128.

It is an arithmetic number, because the mean of its divisors is an integer number (122555692).

Almost surely, 2^1225556780 is an apocalyptic number.

1225556780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1225556780 is an abundant number, since it is smaller than the sum of its proper divisors (1715779828).

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

1225556780 is a wasteful number, since it uses less digits than its factorization.

1225556780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8753993 (or 8753991 counting only the distinct ones).

The product of its (nonzero) digits is 168000, while the sum is 41.

The square root of 1225556780 is about 35007.9530964037. The cubic root of 1225556780 is about 1070.1495642096.

The spelling of 1225556780 in words is "one billion, two hundred twenty-five million, five hundred fifty-six thousand, seven hundred eighty".