537721 has 4 divisors (see below), whose sum is σ = 552292. Its totient is φ = 523152.

The previous prime is 537709. The next prime is 537739. The reversal of 537721 is 127735.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 404496 + 133225 = 636^2 + 365^2 .

It is a cyclic number.

It is not a de Polignac number, because 537721 - 2¹¹ = 535673 is a prime.

It is a Duffinian number.

537721 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (537781) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7230 + ... + 7303.

It is an arithmetic number, because the mean of its divisors is an integer number (138073).

2⁵³⁷⁷²¹ is an apocalyptic number.

It is an amenable number.

537721 is a deficient number, since it is larger than the sum of its proper divisors (14571).

537721 is a wasteful number, since it uses less digits than its factorization.

537721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14570.

The product of its digits is 1470, while the sum is 25.

The square root of 537721 is about 733.2946201903. The cubic root of 537721 is about 81.3178084824.

The spelling of 537721 in words is "five hundred thirty-seven thousand, seven hundred twenty-one".