721684827601 has 4 divisors (see below), whose sum is σ = 759668239600. Its totient is φ = 683701415604.

The previous prime is 721684827583. The next prime is 721684827631. The reversal of 721684827601 is 106728486127.

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 an emirpimes, since its reverse is a distinct semiprime: 106728486127 = 571 ⋅186915037.

It is a cyclic number.

It is not a de Polignac number, because 721684827601 - 2⁷ = 721684827473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721684827631) 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, 18991705971 + ... + 18991706008.

It is an arithmetic number, because the mean of its divisors is an integer number (189917059900).

Almost surely, 2^721684827601 is an apocalyptic number.

It is an amenable number.

721684827601 is a deficient number, since it is larger than the sum of its proper divisors (37983411999).

721684827601 is a wasteful number, since it uses less digits than its factorization.

721684827601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37983411998.

The product of its (nonzero) digits is 1806336, while the sum is 52.

The spelling of 721684827601 in words is "seven hundred twenty-one billion, six hundred eighty-four million, eight hundred twenty-seven thousand, six hundred one".