660138711 has 4 divisors (see below), whose sum is σ = 880184952. Its totient is φ = 440092472.

The previous prime is 660138701. The next prime is 660138749. The reversal of 660138711 is 117831066.

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

It is a cyclic number.

It is not a de Polignac number, because 660138711 - 2²⁶ = 593029847 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660138701) 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, 110023116 + ... + 110023121.

It is an arithmetic number, because the mean of its divisors is an integer number (220046238).

Almost surely, 2^660138711 is an apocalyptic number.

660138711 is a deficient number, since it is larger than the sum of its proper divisors (220046241).

660138711 is a wasteful number, since it uses less digits than its factorization.

660138711 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220046240.

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 660138711 is about 25693.1646746756. The cubic root of 660138711 is about 870.7197597683.

Adding to 660138711 its reverse (117831066), we get a palindrome (777969777).

The spelling of 660138711 in words is "six hundred sixty million, one hundred thirty-eight thousand, seven hundred eleven".