722506509 has 12 divisors (see below), whose sum is σ = 1060729852. Its totient is φ = 473774400.

The previous prime is 722506487. The next prime is 722506517. The reversal of 722506509 is 905605227.

It can be written as a sum of positive squares in 2 ways, for example, as 95004009 + 627502500 = 9747^2 + 25050^2 .

It is a de Polignac number, because none of the positive numbers 2^k-722506509 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 (722506909) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 657472 + ... + 658569.

Almost surely, 2^722506509 is an apocalyptic number.

It is an amenable number.

722506509 is a deficient number, since it is larger than the sum of its proper divisors (338223343).

722506509 is a wasteful number, since it uses less digits than its factorization.

722506509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1316108 (or 1316105 counting only the distinct ones).

The product of its (nonzero) digits is 37800, while the sum is 36.

The square root of 722506509 is about 26879.4811891896. The cubic root of 722506509 is about 897.3198078155.

The spelling of 722506509 in words is "seven hundred twenty-two million, five hundred six thousand, five hundred nine".