642777 has 4 divisors (see below), whose sum is σ = 857040. Its totient is φ = 428516.

The previous prime is 642769. The next prime is 642779. The reversal of 642777 is 777246.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 642777 - 2³ = 642769 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (642779) 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, 107127 + ... + 107132.

It is an arithmetic number, because the mean of its divisors is an integer number (214260).

2⁶⁴²⁷⁷⁷ is an apocalyptic number.

It is an amenable number.

642777 is a deficient number, since it is larger than the sum of its proper divisors (214263).

642777 is a wasteful number, since it uses less digits than its factorization.

642777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214262.

The product of its digits is 16464, while the sum is 33.

The square root of 642777 is about 801.7337463273. The cubic root of 642777 is about 86.3018507803.

The spelling of 642777 in words is "six hundred forty-two thousand, seven hundred seventy-seven".