721687323101 has 4 divisors (see below), whose sum is σ = 721689038400. Its totient is φ = 721685607804.

The previous prime is 721687323079. The next prime is 721687323151. The reversal of 721687323101 is 101323786127.

721687323101 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 721687323101 - 2¹⁰ = 721687322077 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 (721687323151) 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, 252140 + ... + 1227578.

It is an arithmetic number, because the mean of its divisors is an integer number (180422259600).

Almost surely, 2^721687323101 is an apocalyptic number.

It is an amenable number.

721687323101 is a deficient number, since it is larger than the sum of its proper divisors (1715299).

721687323101 is an equidigital number, since it uses as much as digits as its factorization.

721687323101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1715298.

The product of its (nonzero) digits is 84672, while the sum is 41.

The spelling of 721687323101 in words is "seven hundred twenty-one billion, six hundred eighty-seven million, three hundred twenty-three thousand, one hundred one".