721620563 has 8 divisors (see below), whose sum is σ = 749468160. Its totient is φ = 694293640.

The previous prime is 721620547. The next prime is 721620593. The reversal of 721620563 is 365026127.

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

It is a cyclic number.

It is not a de Polignac number, because 721620563 - 2⁴ = 721620547 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721620503) 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, 127343 + ... + 132888.

It is an arithmetic number, because the mean of its divisors is an integer number (93683520).

Almost surely, 2^721620563 is an apocalyptic number.

721620563 is a deficient number, since it is larger than the sum of its proper divisors (27847597).

721620563 is a wasteful number, since it uses less digits than its factorization.

721620563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260337.

The product of its (nonzero) digits is 15120, while the sum is 32.

The square root of 721620563 is about 26862.9961657295. The cubic root of 721620563 is about 896.9528897588.

The spelling of 721620563 in words is "seven hundred twenty-one million, six hundred twenty thousand, five hundred sixty-three".