720221636 has 12 divisors (see below), whose sum is σ = 1301045760. Its totient is φ = 348494280.

The previous prime is 720221633. The next prime is 720221651. The reversal of 720221636 is 636122027.

It is a junction number, because it is equal to n+sod(n) for n = 720221599 and 720221608.

It is not an unprimeable number, because it can be changed into a prime (720221633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2903996 + ... + 2904243.

It is an arithmetic number, because the mean of its divisors is an integer number (108420480).

Almost surely, 2^720221636 is an apocalyptic number.

It is an amenable number.

720221636 is a deficient number, since it is larger than the sum of its proper divisors (580824124).

720221636 is a wasteful number, since it uses less digits than its factorization.

720221636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5808274 (or 5808272 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 29.

The square root of 720221636 is about 26836.9453552374. The cubic root of 720221636 is about 896.3729066007.

The spelling of 720221636 in words is "seven hundred twenty million, two hundred twenty-one thousand, six hundred thirty-six".