755721 has 6 divisors (see below), whose sum is σ = 1091610. Its totient is φ = 503808.

The previous prime is 755719. The next prime is 755737. The reversal of 755721 is 127557.

It can be written as a sum of positive squares in only one way, i.e., 741321 + 14400 = 861^2 + 120^2 .

It is not a de Polignac number, because 755721 - 2¹ = 755719 is a prime.

It is a super-2 number, since 2×755721² = 1142228459682, which contains 22 as substring.

It is a Curzon number.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (755771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 41976 + ... + 41993.

It is an arithmetic number, because the mean of its divisors is an integer number (181935).

2⁷⁵⁵⁷²¹ is an apocalyptic number.

It is an amenable number.

755721 is a deficient number, since it is larger than the sum of its proper divisors (335889).

755721 is a wasteful number, since it uses less digits than its factorization.

755721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83975 (or 83972 counting only the distinct ones).

The product of its digits is 2450, while the sum is 27.

The square root of 755721 is about 869.3221497236. The cubic root of 755721 is about 91.0864613181.

The spelling of 755721 in words is "seven hundred fifty-five thousand, seven hundred twenty-one".