721151 has 4 divisors (see below), whose sum is σ = 722904. Its totient is φ = 719400.

The previous prime is 721141. The next prime is 721159. The reversal of 721151 is 151127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 151127 = 79 ⋅1913.

It is a cyclic number.

It is not a de Polignac number, because 721151 - 2⁶ = 721087 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 (721159) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 116 + ... + 1206.

It is an arithmetic number, because the mean of its divisors is an integer number (180726).

2⁷²¹¹⁵¹ is an apocalyptic number.

721151 is a deficient number, since it is larger than the sum of its proper divisors (1753).

721151 is a wasteful number, since it uses less digits than its factorization.

721151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1752.

The product of its digits is 70, while the sum is 17.

The square root of 721151 is about 849.2060998368. The cubic root of 721151 is about 89.6758296599.

Adding to 721151 its reverse (151127), we get a palindrome (872278).

The spelling of 721151 in words is "seven hundred twenty-one thousand, one hundred fifty-one".