66544505 has 8 divisors (see below), whose sum is σ = 79906824. Its totient is φ = 53200000.

The previous prime is 66544501. The next prime is 66544529. The reversal of 66544505 is 50544566.

It can be written as a sum of positive squares in 4 ways, for example, as 89401 + 66455104 = 299^2 + 8152^2 .

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

It is not a de Polignac number, because 66544505 - 2² = 66544501 is a prime.

It is a super-2 number, since 2×66544505² = 8856342291390050, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66544501) 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, 6005 + ... + 13005.

It is an arithmetic number, because the mean of its divisors is an integer number (9988353).

Almost surely, 2^66544505 is an apocalyptic number.

It is an amenable number.

66544505 is a deficient number, since it is larger than the sum of its proper divisors (13362319).

66544505 is a wasteful number, since it uses less digits than its factorization.

66544505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8907.

The product of its (nonzero) digits is 72000, while the sum is 35.

The square root of 66544505 is about 8157.4815353760. The cubic root of 66544505 is about 405.2323109605.

The spelling of 66544505 in words is "sixty-six million, five hundred forty-four thousand, five hundred five".