55520081 has 4 divisors (see below), whose sum is σ = 55542372. Its totient is φ = 55497792.

The previous prime is 55520051. The next prime is 55520099. The reversal of 55520081 is 18002555.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18002555 = 5 ⋅3600511.

It can be written as a sum of positive squares in 2 ways, for example, as 19219456 + 36300625 = 4384^2 + 6025^2 .

It is a cyclic number.

It is not a de Polignac number, because 55520081 - 2¹⁴ = 55503697 is a prime.

It is a super-2 number, since 2×55520081² = 6164958788493122, which contains 22 as substring.

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 55520081.

It is not an unprimeable number, because it can be changed into a prime (55520051) 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, 6860 + ... + 12573.

It is an arithmetic number, because the mean of its divisors is an integer number (13885593).

Almost surely, 2^55520081 is an apocalyptic number.

It is an amenable number.

55520081 is a deficient number, since it is larger than the sum of its proper divisors (22291).

55520081 is a wasteful number, since it uses less digits than its factorization.

55520081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22290.

The product of its (nonzero) digits is 2000, while the sum is 26.

The square root of 55520081 is about 7451.1798394617. The cubic root of 55520081 is about 381.4901804336.

The spelling of 55520081 in words is "fifty-five million, five hundred twenty thousand, eighty-one".