1213225720 has 32 divisors (see below), whose sum is σ = 3119724000. Its totient is φ = 415963008.

The previous prime is 1213225687. The next prime is 1213225721. The reversal of 1213225720 is 275223121.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213225721) by changing a digit.

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, 2166195 + ... + 2166754.

It is an arithmetic number, because the mean of its divisors is an integer number (97491375).

Almost surely, 2^1213225720 is an apocalyptic number.

1213225720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1213225720 is an abundant number, since it is smaller than the sum of its proper divisors (1906498280).

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

1213225720 is a wasteful number, since it uses less digits than its factorization.

1213225720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4332967 (or 4332963 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 1213225720 is about 34831.3898660389. The cubic root of 1213225720 is about 1066.5483206374.

Adding to 1213225720 its reverse (275223121), we get a palindrome (1488448841).

The spelling of 1213225720 in words is "one billion, two hundred thirteen million, two hundred twenty-five thousand, seven hundred twenty".