646289777 has 4 divisors (see below), whose sum is σ = 738616896. Its totient is φ = 553962660.

The previous prime is 646289771. The next prime is 646289801. The reversal of 646289777 is 777982646.

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 646289777 - 2¹⁴ = 646273393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646289771) 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, 46163549 + ... + 46163562.

It is an arithmetic number, because the mean of its divisors is an integer number (184654224).

Almost surely, 2^646289777 is an apocalyptic number.

It is an amenable number.

646289777 is a deficient number, since it is larger than the sum of its proper divisors (92327119).

646289777 is an equidigital number, since it uses as much as digits as its factorization.

646289777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92327118.

The product of its digits is 7112448, while the sum is 56.

The square root of 646289777 is about 25422.2299769316. The cubic root of 646289777 is about 864.5877849240.

The spelling of 646289777 in words is "six hundred forty-six million, two hundred eighty-nine thousand, seven hundred seventy-seven".