721733503401 has 9 divisors (see below), whose sum is σ = 1042507630749. Its totient is φ = 481153969836.

The previous prime is 721733503399. The next prime is 721733503417. The reversal of 721733503401 is 104305337127.

The square root of 721733503401 is 849549.

It is a perfect power (a square), and thus also a powerful number.

721733503401 is a `hidden beast` number, since 7 + 217 + 3 + 35 + 0 + 3 + 401 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 721733503401 - 2¹ = 721733503399 is a prime.

It is not an unprimeable number, because it can be changed into a prime (721733503801) 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 8 ways as a sum of consecutive naturals, for example, 2407056 + ... + 2690238.

Almost surely, 2^721733503401 is an apocalyptic number.

721733503401 is the 849549-th square number.

721733503401 is the 424775-th centered octagonal number.

It is an amenable number.

721733503401 is a deficient number, since it is larger than the sum of its proper divisors (320774127348).

721733503401 is an frugal number, since it uses more digits than its factorization.

721733503401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 566372 (or 283186 counting only the distinct ones).

The product of its (nonzero) digits is 52920, while the sum is 36.

Multiplying 721733503401 by its sum of digits (36), we get a square (25982406122436 = 5097294²).

The spelling of 721733503401 in words is "seven hundred twenty-one billion, seven hundred thirty-three million, five hundred three thousand, four hundred one".