55812842581 has 2 divisors, whose sum is σ = 55812842582. Its totient is φ = 55812842580.

The previous prime is 55812842549. The next prime is 55812842639. The reversal of 55812842581 is 18524821855.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50737562500 + 5075280081 = 225250^2 + 71241^2 .

It is a cyclic number.

It is not a de Polignac number, because 55812842581 - 2⁵ = 55812842549 is a prime.

It is a super-2 number, since 2×55812842581² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55812842081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27906421290 + 27906421291.

It is an arithmetic number, because the mean of its divisors is an integer number (27906421291).

Almost surely, 2^55812842581 is an apocalyptic number.

It is an amenable number.

55812842581 is a deficient number, since it is larger than the sum of its proper divisors (1).

55812842581 is an equidigital number, since it uses as much as digits as its factorization.

55812842581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1024000, while the sum is 49.

The spelling of 55812842581 in words is "fifty-five billion, eight hundred twelve million, eight hundred forty-two thousand, five hundred eighty-one".