720011605 has 4 divisors (see below), whose sum is σ = 864013932. Its totient is φ = 576009280.

The previous prime is 720011603. The next prime is 720011627. The reversal of 720011605 is 506110027.

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 390734289 + 329277316 = 19767^2 + 18146^2 .

It is not a de Polignac number, because 720011605 - 2¹ = 720011603 is a prime.

It is a super-2 number, since 2×720011605² = 1036833422669352050, which contains 22 as substring.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (720011603) 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, 72001156 + ... + 72001165.

It is an arithmetic number, because the mean of its divisors is an integer number (216003483).

Almost surely, 2^720011605 is an apocalyptic number.

It is an amenable number.

720011605 is a deficient number, since it is larger than the sum of its proper divisors (144002327).

720011605 is a wasteful number, since it uses less digits than its factorization.

720011605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144002326.

The product of its (nonzero) digits is 420, while the sum is 22.

The square root of 720011605 is about 26833.0319755334. The cubic root of 720011605 is about 896.2857647209.

The spelling of 720011605 in words is "seven hundred twenty million, eleven thousand, six hundred five".