1225521920 has 72 divisors (see below), whose sum is σ = 3354890784. Its totient is φ = 420175872.

The previous prime is 1225521919. The next prime is 1225521937. The reversal of 1225521920 is 291255221.

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 7 ways as a sum of consecutive naturals, for example, 59429 + ... + 77348.

Almost surely, 2^1225521920 is an apocalyptic number.

1225521920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1225521920 is an abundant number, since it is smaller than the sum of its proper divisors (2129368864).

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

1225521920 is an equidigital number, since it uses as much as digits as its factorization.

1225521920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136805 (or 136791 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 29.

The square root of 1225521920 is about 35007.4552059986. The cubic root of 1225521920 is about 1070.1394175921.

The spelling of 1225521920 in words is "one billion, two hundred twenty-five million, five hundred twenty-one thousand, nine hundred twenty".