55808581 has 2 divisors, whose sum is σ = 55808582. Its totient is φ = 55808580.

The previous prime is 55808579. The next prime is 55808647. The reversal of 55808581 is 18580855.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37822500 + 17986081 = 6150^2 + 4241^2 .

It is a cyclic number.

It is not a de Polignac number, because 55808581 - 2¹ = 55808579 is a prime.

It is a super-2 number, since 2×55808581² = 6229195426467122, which contains 22 as substring.

Together with 55808579, 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 (55808551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27904290 + 27904291.

It is an arithmetic number, because the mean of its divisors is an integer number (27904291).

Almost surely, 2^55808581 is an apocalyptic number.

It is an amenable number.

55808581 is a deficient number, since it is larger than the sum of its proper divisors (1).

55808581 is an equidigital number, since it uses as much as digits as its factorization.

55808581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64000, while the sum is 40.

The square root of 55808581 is about 7470.5141054682. The cubic root of 55808581 is about 382.1498206219.

It can be divided in two parts, 5580 and 8581, that added together give a square (14161 = 119²).

The spelling of 55808581 in words is "fifty-five million, eight hundred eight thousand, five hundred eighty-one".