721654716054173 has 4 divisors (see below), whose sum is σ = 787259690240928. Its totient is φ = 656049741867420.

The previous prime is 721654716054163. The next prime is 721654716054197. The reversal of 721654716054173 is 371450617456127.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 721654716054173 - 2⁴ = 721654716054157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721654716054163) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32802487093361 + ... + 32802487093382.

It is an arithmetic number, because the mean of its divisors is an integer number (196814922560232).

Almost surely, 2^{721654716054173} is an apocalyptic number.

It is an amenable number.

721654716054173 is a deficient number, since it is larger than the sum of its proper divisors (65604974186755).

721654716054173 is a wasteful number, since it uses less digits than its factorization.

721654716054173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65604974186754.

The product of its (nonzero) digits is 29635200, while the sum is 59.

The spelling of 721654716054173 in words is "seven hundred twenty-one trillion, six hundred fifty-four billion, seven hundred sixteen million, fifty-four thousand, one hundred seventy-three".