646622777 has 4 divisors (see below), whose sum is σ = 661660560. Its totient is φ = 631584996.

The previous prime is 646622749. The next prime is 646622789. The reversal of 646622777 is 777226646.

646622777 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 646622777 - 2²² = 642428473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646622747) 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, 7518827 + ... + 7518912.

It is an arithmetic number, because the mean of its divisors is an integer number (165415140).

Almost surely, 2^646622777 is an apocalyptic number.

It is an amenable number.

646622777 is a deficient number, since it is larger than the sum of its proper divisors (15037783).

646622777 is a wasteful number, since it uses less digits than its factorization.

646622777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15037782.

The product of its digits is 1185408, while the sum is 47.

The square root of 646622777 is about 25428.7785196222. The cubic root of 646622777 is about 864.7362520197.

The spelling of 646622777 in words is "six hundred forty-six million, six hundred twenty-two thousand, seven hundred seventy-seven".