56721753 has 24 divisors (see below), whose sum is σ = 89799840. Its totient is φ = 34215360.

The previous prime is 56721677. The next prime is 56721757. The reversal of 56721753 is 35712765.

56721753 is a `hidden beast` number, since 567 + 21 + 75 + 3 = 666.

It is not a de Polignac number, because 56721753 - 2⁹ = 56721241 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (56721757) 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 23 ways as a sum of consecutive naturals, for example, 21838 + ... + 24296.

It is an arithmetic number, because the mean of its divisors is an integer number (3741660).

Almost surely, 2^56721753 is an apocalyptic number.

It is an amenable number.

56721753 is a deficient number, since it is larger than the sum of its proper divisors (33078087).

56721753 is a wasteful number, since it uses less digits than its factorization.

56721753 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2709 (or 2706 counting only the distinct ones).

The product of its digits is 44100, while the sum is 36.

The square root of 56721753 is about 7531.3845340681. The cubic root of 56721753 is about 384.2228727360. Note that the first 3 decimals are identical.

The spelling of 56721753 in words is "fifty-six million, seven hundred twenty-one thousand, seven hundred fifty-three".