56731709 has 4 divisors (see below), whose sum is σ = 56750304. Its totient is φ = 56713116.

The previous prime is 56731699. The next prime is 56731729. The reversal of 56731709 is 90713765.

56731709 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, and also an emirpimes, since its reverse is a distinct semiprime: 90713765 = 5 ⋅18142753.

It is a cyclic number.

It is not a de Polignac number, because 56731709 - 2¹⁶ = 56666173 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56731729) 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, 3527 + ... + 11220.

It is an arithmetic number, because the mean of its divisors is an integer number (14187576).

Almost surely, 2^56731709 is an apocalyptic number.

It is an amenable number.

56731709 is a deficient number, since it is larger than the sum of its proper divisors (18595).

56731709 is a wasteful number, since it uses less digits than its factorization.

56731709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18594.

The product of its (nonzero) digits is 39690, while the sum is 38.

The square root of 56731709 is about 7532.0454725128. The cubic root of 56731709 is about 384.2453514673.

The spelling of 56731709 in words is "fifty-six million, seven hundred thirty-one thousand, seven hundred nine".