6640842777 has 8 divisors (see below), whose sum is σ = 8975751264. Its totient is φ = 4366581408.

The previous prime is 6640842773. The next prime is 6640842829. The reversal of 6640842777 is 7772480466.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 6640842777 - 2² = 6640842773 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6640842773) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15161523 + ... + 15161960.

It is an arithmetic number, because the mean of its divisors is an integer number (1121968908).

Almost surely, 2^6640842777 is an apocalyptic number.

It is an amenable number.

6640842777 is a deficient number, since it is larger than the sum of its proper divisors (2334908487).

6640842777 is a wasteful number, since it uses less digits than its factorization.

6640842777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30323559.

The product of its (nonzero) digits is 3161088, while the sum is 51.

The square root of 6640842777 is about 81491.3662727531. The cubic root of 6640842777 is about 1879.6387921750.

The spelling of 6640842777 in words is "six billion, six hundred forty million, eight hundred forty-two thousand, seven hundred seventy-seven".