1225643520 has 80 divisors (see below), whose sum is σ = 3918253680. Its totient is φ = 326836224.

The previous prime is 1225643483. The next prime is 1225643533. The reversal of 1225643520 is 253465221.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

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, 72115 + ... + 87474.

It is an arithmetic number, because the mean of its divisors is an integer number (48978171).

Almost surely, 2^1225643520 is an apocalyptic number.

1225643520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1225643520 is an abundant number, since it is smaller than the sum of its proper divisors (2692610160).

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

1225643520 is an equidigital number, since it uses as much as digits as its factorization.

1225643520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159615 (or 159599 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 30.

The square root of 1225643520 is about 35009.1919358331. The cubic root of 1225643520 is about 1070.1748105806.

The spelling of 1225643520 in words is "one billion, two hundred twenty-five million, six hundred forty-three thousand, five hundred twenty".