721562 has 4 divisors (see below), whose sum is σ = 1082346. Its totient is φ = 360780.

The previous prime is 721561. The next prime is 721571. The reversal of 721562 is 265127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 265127 = 47 ⋅5641.

It can be written as a sum of positive squares in only one way, i.e., 654481 + 67081 = 809^2 + 259^2 .

It is not an unprimeable number, because it can be changed into a prime (721561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 180389 + ... + 180392.

2⁷²¹⁵⁶² is an apocalyptic number.

721562 is a deficient number, since it is larger than the sum of its proper divisors (360784).

721562 is a wasteful number, since it uses less digits than its factorization.

721562 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 360783.

The product of its digits is 840, while the sum is 23.

The square root of 721562 is about 849.4480560929. The cubic root of 721562 is about 89.6928625080.

Adding to 721562 its reverse (265127), we get a palindrome (986689).

The spelling of 721562 in words is "seven hundred twenty-one thousand, five hundred sixty-two".