66536281 has 4 divisors (see below), whose sum is σ = 76041472. Its totient is φ = 57031092.

The previous prime is 66536243. The next prime is 66536291. The reversal of 66536281 is 18263566.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18263566 = 2 ⋅9131783.

It is a cyclic number.

It is not a de Polignac number, because 66536281 - 2⁹ = 66535769 is a prime.

It is a super-2 number, since 2×66536281² = 8854153378621922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66536281.

It is not an unprimeable number, because it can be changed into a prime (66536221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4752585 + ... + 4752598.

It is an arithmetic number, because the mean of its divisors is an integer number (19010368).

Almost surely, 2^66536281 is an apocalyptic number.

It is an amenable number.

66536281 is a deficient number, since it is larger than the sum of its proper divisors (9505191).

66536281 is an equidigital number, since it uses as much as digits as its factorization.

66536281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9505190.

The product of its digits is 51840, while the sum is 37.

The square root of 66536281 is about 8156.9774426561. The cubic root of 66536281 is about 405.2156165301.

The spelling of 66536281 in words is "sixty-six million, five hundred thirty-six thousand, two hundred eighty-one".