55720645 has 12 divisors (see below), whose sum is σ = 71031204. Its totient is φ = 41953280.

The previous prime is 55720627. The next prime is 55720657. The reversal of 55720645 is 54602755.

55720645 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 6 ways, for example, as 381924 + 55338721 = 618^2 + 7439^2 .

It is not a de Polignac number, because 55720645 - 2¹³ = 55712453 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 55720645.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 17836 + ... + 20725.

It is an arithmetic number, because the mean of its divisors is an integer number (5919267).

Almost surely, 2^55720645 is an apocalyptic number.

It is an amenable number.

55720645 is a deficient number, since it is larger than the sum of its proper divisors (15310559).

55720645 is a wasteful number, since it uses less digits than its factorization.

55720645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38600 (or 38583 counting only the distinct ones).

The product of its (nonzero) digits is 42000, while the sum is 34.

The square root of 55720645 is about 7464.6262465042. The cubic root of 55720645 is about 381.9490008943.

It can be divided in two parts, 55720 and 645, that added together give a palindrome (56365).

The spelling of 55720645 in words is "fifty-five million, seven hundred twenty thousand, six hundred forty-five".