56987729 has 4 divisors (see below), whose sum is σ = 57008484. Its totient is φ = 56966976.

The previous prime is 56987713. The next prime is 56987741. The reversal of 56987729 is 92778965.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 92778965 = 5 ⋅18555793.

It can be written as a sum of positive squares in 2 ways, for example, as 19140625 + 37847104 = 4375^2 + 6152^2 .

It is a cyclic number.

It is not a de Polignac number, because 56987729 - 2⁴ = 56987713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (56987759) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5492 + ... + 12005.

It is an arithmetic number, because the mean of its divisors is an integer number (14252121).

Almost surely, 2^56987729 is an apocalyptic number.

It is an amenable number.

56987729 is a deficient number, since it is larger than the sum of its proper divisors (20755).

56987729 is a wasteful number, since it uses less digits than its factorization.

56987729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20754.

The product of its digits is 1905120, while the sum is 53.

The square root of 56987729 is about 7549.0217247005. The cubic root of 56987729 is about 384.8224942115.

The spelling of 56987729 in words is "fifty-six million, nine hundred eighty-seven thousand, seven hundred twenty-nine".