66681145 has 8 divisors (see below), whose sum is σ = 80096904. Its totient is φ = 53291904.

The previous prime is 66681143. The next prime is 66681149. The reversal of 66681145 is 54118666.

It can be written as a sum of positive squares in 4 ways, for example, as 356409 + 66324736 = 597^2 + 8144^2 .

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 66681145 - 2¹ = 66681143 is a prime.

It is a super-2 number, since 2×66681145² = 8892750197022050, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66681143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 594 + ... + 11563.

It is an arithmetic number, because the mean of its divisors is an integer number (10012113).

Almost surely, 2^66681145 is an apocalyptic number.

It is an amenable number.

66681145 is a deficient number, since it is larger than the sum of its proper divisors (13415759).

66681145 is a wasteful number, since it uses less digits than its factorization.

66681145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13259.

The product of its digits is 34560, while the sum is 37.

The square root of 66681145 is about 8165.8523743697. The cubic root of 66681145 is about 405.5094842962.

The spelling of 66681145 in words is "sixty-six million, six hundred eighty-one thousand, one hundred forty-five".