55781573 has 4 divisors (see below), whose sum is σ = 59062860. Its totient is φ = 52500288.

The previous prime is 55781569. The next prime is 55781581. The reversal of 55781573 is 37518755.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 37518755 = 5 ⋅7503751.

It can be written as a sum of positive squares in 2 ways, for example, as 40742689 + 15038884 = 6383^2 + 3878^2 .

It is a cyclic number.

It is not a de Polignac number, because 55781573 - 2² = 55781569 is a prime.

It is a super-2 number, since 2×55781573² = 6223167772708658, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 55781573.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55781543) 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, 1640618 + ... + 1640651.

It is an arithmetic number, because the mean of its divisors is an integer number (14765715).

Almost surely, 2^55781573 is an apocalyptic number.

It is an amenable number.

55781573 is a deficient number, since it is larger than the sum of its proper divisors (3281287).

55781573 is a wasteful number, since it uses less digits than its factorization.

55781573 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3281286.

The product of its digits is 147000, while the sum is 41.

The square root of 55781573 is about 7468.7062467338. The cubic root of 55781573 is about 382.0881648242.

The spelling of 55781573 in words is "fifty-five million, seven hundred eighty-one thousand, five hundred seventy-three".