66655543 has 8 divisors (see below), whose sum is σ = 69601680. Its totient is φ = 63752640.

The previous prime is 66655513. The next prime is 66655573. The reversal of 66655543 is 34555666.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66655513) and next prime (66655573).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66655543 - 2²¹ = 64558391 is a prime.

It is a super-2 number, since 2×66655543² = 8885922825249698, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 66655496 and 66655505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66655513) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7638 + ... + 13843.

It is an arithmetic number, because the mean of its divisors is an integer number (8700210).

Almost surely, 2^66655543 is an apocalyptic number.

66655543 is a deficient number, since it is larger than the sum of its proper divisors (2946137).

66655543 is a wasteful number, since it uses less digits than its factorization.

66655543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21617.

The product of its digits is 324000, while the sum is 40.

The square root of 66655543 is about 8164.2845981752. The cubic root of 66655543 is about 405.4575796546.

The spelling of 66655543 in words is "sixty-six million, six hundred fifty-five thousand, five hundred forty-three".