1640641915 has 32 divisors (see below), whose sum is σ = 2176860096. Its totient is φ = 1177128960.

The previous prime is 1640641913. The next prime is 1640641921. The reversal of 1640641915 is 5191460461.

It is not a de Polignac number, because 1640641915 - 2¹ = 1640641913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1640641913) 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 31 ways as a sum of consecutive naturals, for example, 1721079 + ... + 1722031.

It is an arithmetic number, because the mean of its divisors is an integer number (68026878).

Almost surely, 2^1640641915 is an apocalyptic number.

1640641915 is a deficient number, since it is larger than the sum of its proper divisors (536218181).

1640641915 is a wasteful number, since it uses less digits than its factorization.

1640641915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1359.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 1640641915 is about 40504.8381678041. The cubic root of 1640641915 is about 1179.4275483881.

The spelling of 1640641915 in words is "one billion, six hundred forty million, six hundred forty-one thousand, nine hundred fifteen".