55945451581 has 2 divisors, whose sum is σ = 55945451582. Its totient is φ = 55945451580.

The previous prime is 55945451491. The next prime is 55945451603. The reversal of 55945451581 is 18515454955.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46308888025 + 9636563556 = 215195^2 + 98166^2 .

It is a cyclic number.

It is not a de Polignac number, because 55945451581 - 2³⁵ = 21585713213 is a prime.

It is a super-2 number, since 2×55945451581² (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 (55945455581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27972725790 + 27972725791.

It is an arithmetic number, because the mean of its divisors is an integer number (27972725791).

Almost surely, 2^55945451581 is an apocalyptic number.

It is an amenable number.

55945451581 is a deficient number, since it is larger than the sum of its proper divisors (1).

55945451581 is an equidigital number, since it uses as much as digits as its factorization.

55945451581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3600000, while the sum is 52.

The spelling of 55945451581 in words is "fifty-five billion, nine hundred forty-five million, four hundred fifty-one thousand, five hundred eighty-one".