55520731 has 4 divisors (see below), whose sum is σ = 63452272. Its totient is φ = 47589192.

The previous prime is 55520723. The next prime is 55520741. The reversal of 55520731 is 13702555.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13702555 = 5 ⋅2740511.

It is not a de Polignac number, because 55520731 - 2³ = 55520723 is a prime.

It is a super-3 number, since 3×55520731³ (a number of 24 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

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 55520731.

It is not an unprimeable number, because it can be changed into a prime (55520701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3965760 + ... + 3965773.

It is an arithmetic number, because the mean of its divisors is an integer number (15863068).

Almost surely, 2^55520731 is an apocalyptic number.

55520731 is a deficient number, since it is larger than the sum of its proper divisors (7931541).

55520731 is an equidigital number, since it uses as much as digits as its factorization.

55520731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7931540.

The product of its (nonzero) digits is 5250, while the sum is 28.

The square root of 55520731 is about 7451.2234565875. The cubic root of 55520731 is about 381.4916691901.

The spelling of 55520731 in words is "fifty-five million, five hundred twenty thousand, seven hundred thirty-one".