66013641 has 12 divisors (see below), whose sum is σ = 96337332. Its totient is φ = 43554816.

The previous prime is 66013639. The next prime is 66013667. The reversal of 66013641 is 14631066.

66013641 is a `hidden beast` number, since 6 + 6 + 0 + 13 + 641 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 23242041 + 42771600 = 4821^2 + 6540^2 .

It is not a de Polignac number, because 66013641 - 2¹ = 66013639 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66013631) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 36936 + ... + 38681.

It is an arithmetic number, because the mean of its divisors is an integer number (8028111).

Almost surely, 2^66013641 is an apocalyptic number.

It is an amenable number.

66013641 is a deficient number, since it is larger than the sum of its proper divisors (30323691).

66013641 is a wasteful number, since it uses less digits than its factorization.

66013641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75720 (or 75717 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 66013641 is about 8124.8779067750. The cubic root of 66013641 is about 404.1518418388.

The spelling of 66013641 in words is "sixty-six million, thirteen thousand, six hundred forty-one".