664877811 has 16 divisors (see below), whose sum is σ = 1004944640. Its totient is φ = 387620640.

The previous prime is 664877749. The next prime is 664877821. The reversal of 664877811 is 118778466.

It is not a de Polignac number, because 664877811 - 2⁷ = 664877683 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664877821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 447895 + ... + 449376.

It is an arithmetic number, because the mean of its divisors is an integer number (62809040).

Almost surely, 2^664877811 is an apocalyptic number.

664877811 is a deficient number, since it is larger than the sum of its proper divisors (340066829).

664877811 is a wasteful number, since it uses less digits than its factorization.

664877811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 897306.

The product of its digits is 451584, while the sum is 48.

The square root of 664877811 is about 25785.2246645244. The cubic root of 664877811 is about 872.7984101449.

It can be divided in two parts, 664 and 877811, that added together give a triangular number (878475 = T₁₃₂₅).

The spelling of 664877811 in words is "six hundred sixty-four million, eight hundred seventy-seven thousand, eight hundred eleven".