66514381 has 4 divisors (see below), whose sum is σ = 66593212. Its totient is φ = 66435552.

The previous prime is 66514379. The next prime is 66514391. The reversal of 66514381 is 18341566.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19660356 + 46854025 = 4434^2 + 6845^2 .

It is a cyclic number.

It is not a de Polignac number, because 66514381 - 2¹ = 66514379 is a prime.

It is a super-2 number, since 2×66514381² = 8848325759626322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66514361) 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 in 3 ways as a sum of consecutive naturals, for example, 38136 + ... + 39841.

It is an arithmetic number, because the mean of its divisors is an integer number (16648303).

Almost surely, 2^66514381 is an apocalyptic number.

It is an amenable number.

66514381 is a deficient number, since it is larger than the sum of its proper divisors (78831).

66514381 is an equidigital number, since it uses as much as digits as its factorization.

66514381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78830.

The product of its digits is 17280, while the sum is 34.

The square root of 66514381 is about 8155.6349231682. The cubic root of 66514381 is about 405.1711535911.

The spelling of 66514381 in words is "sixty-six million, five hundred fourteen thousand, three hundred eighty-one".