721958 has 4 divisors (see below), whose sum is σ = 1082940. Its totient is φ = 360978.

The previous prime is 721951. The next prime is 721961. The reversal of 721958 is 859127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 859127 = 137 ⋅6271.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 721958.

It is not an unprimeable number, because it can be changed into a prime (721951) by changing a digit.

721958 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 as a sum of consecutive naturals, namely, 180488 + ... + 180491.

It is an arithmetic number, because the mean of its divisors is an integer number (270735).

2⁷²¹⁹⁵⁸ is an apocalyptic number.

721958 is a deficient number, since it is larger than the sum of its proper divisors (360982).

721958 is a wasteful number, since it uses less digits than its factorization.

721958 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360981.

The product of its digits is 5040, while the sum is 32.

The square root of 721958 is about 849.6811166549. The cubic root of 721958 is about 89.7092676023.

The spelling of 721958 in words is "seven hundred twenty-one thousand, nine hundred fifty-eight".