721705021101 has 24 divisors (see below), whose sum is σ = 1050754250624. Its totient is φ = 477318290400.

The previous prime is 721705021097. The next prime is 721705021139. The reversal of 721705021101 is 101120507127.

It is not a de Polignac number, because 721705021101 - 2² = 721705021097 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 (721705121101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 678000 + ... + 1379526.

Almost surely, 2^721705021101 is an apocalyptic number.

It is an amenable number.

721705021101 is a deficient number, since it is larger than the sum of its proper divisors (329049229523).

721705021101 is a wasteful number, since it uses less digits than its factorization.

721705021101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 702441 (or 702438 counting only the distinct ones).

The product of its (nonzero) digits is 980, while the sum is 27.

Adding to 721705021101 its reverse (101120507127), we get a palindrome (822825528228).

The spelling of 721705021101 in words is "seven hundred twenty-one billion, seven hundred five million, twenty-one thousand, one hundred one".