721628231 has 8 divisors (see below), whose sum is σ = 747300384. Its totient is φ = 696402720.

The previous prime is 721628207. The next prime is 721628267. The reversal of 721628231 is 132826127.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-721628231 is a prime.

It is a super-2 number, since 2×721628231² = 1041494607552378722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721621231) 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, 108371 + ... + 114836.

It is an arithmetic number, because the mean of its divisors is an integer number (93412548).

Almost surely, 2^721628231 is an apocalyptic number.

721628231 is a deficient number, since it is larger than the sum of its proper divisors (25672153).

721628231 is a wasteful number, since it uses less digits than its factorization.

721628231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223321.

The product of its digits is 8064, while the sum is 32.

The square root of 721628231 is about 26863.1388895639. The cubic root of 721628231 is about 896.9560667795.

The spelling of 721628231 in words is "seven hundred twenty-one million, six hundred twenty-eight thousand, two hundred thirty-one".