66015640111 has 4 divisors (see below), whose sum is σ = 66095273800. Its totient is φ = 65936006424.

The previous prime is 66015640109. The next prime is 66015640121. The reversal of 66015640111 is 11104651066.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11104651066 = 2 ⋅5552325533.

It is a cyclic number.

It is not a de Polignac number, because 66015640111 - 2¹ = 66015640109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66015640121) 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, 39815601 + ... + 39817258.

It is an arithmetic number, because the mean of its divisors is an integer number (16523818450).

Almost surely, 2^66015640111 is an apocalyptic number.

66015640111 is a deficient number, since it is larger than the sum of its proper divisors (79633689).

66015640111 is an equidigital number, since it uses as much as digits as its factorization.

66015640111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79633688.

The product of its (nonzero) digits is 4320, while the sum is 31.

The spelling of 66015640111 in words is "sixty-six billion, fifteen million, six hundred forty thousand, one hundred eleven".