721251 has 8 divisors (see below), whose sum is σ = 1068560. Its totient is φ = 480816.

The previous prime is 721243. The next prime is 721261. The reversal of 721251 is 152127.

It is not a de Polignac number, because 721251 - 2³ = 721243 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (721261) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13330 + ... + 13383.

It is an arithmetic number, because the mean of its divisors is an integer number (133570).

2⁷²¹²⁵¹ is an apocalyptic number.

721251 is a deficient number, since it is larger than the sum of its proper divisors (347309).

721251 is a wasteful number, since it uses less digits than its factorization.

721251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26722 (or 26716 counting only the distinct ones).

The product of its digits is 140, while the sum is 18.

The square root of 721251 is about 849.2649763178. The cubic root of 721251 is about 89.6799745008.

Adding to 721251 its reverse (152127), we get a palindrome (873378).

The spelling of 721251 in words is "seven hundred twenty-one thousand, two hundred fifty-one".