55520581 has 2 divisors, whose sum is σ = 55520582. Its totient is φ = 55520580.

The previous prime is 55520579. The next prime is 55520599. The reversal of 55520581 is 18502555.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55368481 + 152100 = 7441^2 + 390^2 .

It is a cyclic number.

It is not a de Polignac number, because 55520581 - 2¹ = 55520579 is a prime.

It is a super-2 number, since 2×55520581² = 6165069829155122, which contains 22 as substring.

Together with 55520579, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55520501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27760290 + 27760291.

It is an arithmetic number, because the mean of its divisors is an integer number (27760291).

Almost surely, 2^55520581 is an apocalyptic number.

It is an amenable number.

55520581 is a deficient number, since it is larger than the sum of its proper divisors (1).

55520581 is an equidigital number, since it uses as much as digits as its factorization.

55520581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10000, while the sum is 31.

The square root of 55520581 is about 7451.2133911196. The cubic root of 55520581 is about 381.4913256320.

The spelling of 55520581 in words is "fifty-five million, five hundred twenty thousand, five hundred eighty-one".