722521537 has 4 divisors (see below), whose sum is σ = 725130196. Its totient is φ = 719912880.

The previous prime is 722521529. The next prime is 722521543. The reversal of 722521537 is 735125227.

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 337420161 + 385101376 = 18369^2 + 19624^2 .

It is a cyclic number.

It is not a de Polignac number, because 722521537 - 2³ = 722521529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (722521567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1303914 + ... + 1304467.

It is an arithmetic number, because the mean of its divisors is an integer number (181282549).

Almost surely, 2^722521537 is an apocalyptic number.

It is an amenable number.

722521537 is a deficient number, since it is larger than the sum of its proper divisors (2608659).

722521537 is a wasteful number, since it uses less digits than its factorization.

722521537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2608658.

The product of its digits is 29400, while the sum is 34.

The square root of 722521537 is about 26879.7607318220. The cubic root of 722521537 is about 897.3260291336.

The spelling of 722521537 in words is "seven hundred twenty-two million, five hundred twenty-one thousand, five hundred thirty-seven".