1640674787 has 2 divisors, whose sum is σ = 1640674788. Its totient is φ = 1640674786.

The previous prime is 1640674769. The next prime is 1640674823. The reversal of 1640674787 is 7874760461.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1640674787 - 2⁶ = 1640674723 is a prime.

It is not a weakly prime, because it can be changed into another prime (1640674747) 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 as a sum of consecutive naturals, namely, 820337393 + 820337394.

It is an arithmetic number, because the mean of its divisors is an integer number (820337394).

Almost surely, 2^1640674787 is an apocalyptic number.

1640674787 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640674787 is an equidigital number, since it uses as much as digits as its factorization.

1640674787 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1580544, while the sum is 50.

The square root of 1640674787 is about 40505.2439444574. The cubic root of 1640674787 is about 1179.4354253625.

It can be divided in two parts, 1640674 and 787, that added together give a palindrome (1641461).

The spelling of 1640674787 in words is "one billion, six hundred forty million, six hundred seventy-four thousand, seven hundred eighty-seven".