66857711 has 4 divisors (see below), whose sum is σ = 69764592. Its totient is φ = 63950832.

The previous prime is 66857701. The next prime is 66857723. The reversal of 66857711 is 11775866.

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 66857711 - 2²² = 62663407 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 (66857701) 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, 1453406 + ... + 1453451.

It is an arithmetic number, because the mean of its divisors is an integer number (17441148).

Almost surely, 2^66857711 is an apocalyptic number.

66857711 is a deficient number, since it is larger than the sum of its proper divisors (2906881).

66857711 is a wasteful number, since it uses less digits than its factorization.

66857711 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2906880.

The product of its digits is 70560, while the sum is 41.

The square root of 66857711 is about 8176.6564682638. The cubic root of 66857711 is about 405.8670870549.

The spelling of 66857711 in words is "sixty-six million, eight hundred fifty-seven thousand, seven hundred eleven".