640776241 has 16 divisors (see below), whose sum is σ = 742017024. Its totient is φ = 542001744.

The previous prime is 640776221. The next prime is 640776247. The reversal of 640776241 is 142677046.

It is a cyclic number.

It is not a de Polignac number, because 640776241 - 2⁵ = 640776209 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 640776241.

It is not an unprimeable number, because it can be changed into a prime (640776247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 210456 + ... + 213478.

It is an arithmetic number, because the mean of its divisors is an integer number (46376064).

Almost surely, 2^640776241 is an apocalyptic number.

It is an amenable number.

640776241 is a deficient number, since it is larger than the sum of its proper divisors (101240783).

640776241 is a wasteful number, since it uses less digits than its factorization.

640776241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3420.

The product of its (nonzero) digits is 56448, while the sum is 37.

The square root of 640776241 is about 25313.5584420682. The cubic root of 640776241 is about 862.1221436942.

It can be divided in two parts, 640 and 776241, that added together give a triangular number (776881 = T₁₂₄₆).

The spelling of 640776241 in words is "six hundred forty million, seven hundred seventy-six thousand, two hundred forty-one".