721377 has 6 divisors (see below), whose sum is σ = 1042002. Its totient is φ = 480912.

The previous prime is 721363. The next prime is 721379. The reversal of 721377 is 773127.

It can be written as a sum of positive squares in only one way, i.e., 720801 + 576 = 849^2 + 24^2 .

It is not a de Polignac number, because 721377 - 2¹⁴ = 704993 is a prime.

It is a super-2 number, since 2×721377² = 1040769552258, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 721377.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 721377.

It is not an unprimeable number, because it can be changed into a prime (721379) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 40068 + ... + 40085.

It is an arithmetic number, because the mean of its divisors is an integer number (173667).

2⁷²¹³⁷⁷ is an apocalyptic number.

It is an amenable number.

721377 is a deficient number, since it is larger than the sum of its proper divisors (320625).

721377 is a wasteful number, since it uses less digits than its factorization.

721377 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80159 (or 80156 counting only the distinct ones).

The product of its digits is 2058, while the sum is 27.

The square root of 721377 is about 849.3391548728. The cubic root of 721377 is about 89.6851964549.

The spelling of 721377 in words is "seven hundred twenty-one thousand, three hundred seventy-seven", and thus it is an iban number.