720726649 has 4 divisors (see below), whose sum is σ = 721021264. Its totient is φ = 720432036.

The previous prime is 720726637. The next prime is 720726673. The reversal of 720726649 is 946627027.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 720726649 - 2⁷ = 720726521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (720726619) 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, 143607 + ... + 148540.

It is an arithmetic number, because the mean of its divisors is an integer number (180255316).

Almost surely, 2^720726649 is an apocalyptic number.

It is an amenable number.

720726649 is a deficient number, since it is larger than the sum of its proper divisors (294615).

720726649 is a wasteful number, since it uses less digits than its factorization.

720726649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 294614.

The product of its (nonzero) digits is 254016, while the sum is 43.

The square root of 720726649 is about 26846.3526200488. The cubic root of 720726649 is about 896.5823672187.

It can be divided in two parts, 7207 and 26649, that added together give a square (33856 = 184²).

The spelling of 720726649 in words is "seven hundred twenty million, seven hundred twenty-six thousand, six hundred forty-nine".