721253 has 8 divisors (see below), whose sum is σ = 785400. Its totient is φ = 658368.

The previous prime is 721243. The next prime is 721261. The reversal of 721253 is 352127.

It can be written as a sum of positive squares in 4 ways, for example, as 146689 + 574564 = 383^2 + 758^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 721253 - 2⁸ = 720997 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 (721213) 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, 1163 + ... + 1671.

It is an arithmetic number, because the mean of its divisors is an integer number (98175).

2⁷²¹²⁵³ is an apocalyptic number.

It is an amenable number.

721253 is a deficient number, since it is larger than the sum of its proper divisors (64147).

721253 is a wasteful number, since it uses less digits than its factorization.

721253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 631.

The product of its digits is 420, while the sum is 20.

The square root of 721253 is about 849.2661538057. The cubic root of 721253 is about 89.6800573937.

The spelling of 721253 in words is "seven hundred twenty-one thousand, two hundred fifty-three".