1640312009 has 32 divisors (see below), whose sum is σ = 2036094720. Its totient is φ = 1289945088.

The previous prime is 1640311973. The next prime is 1640312027. The reversal of 1640312009 is 9002130461.

It is a cyclic number.

It is not a de Polignac number, because 1640312009 - 2¹² = 1640307913 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1640312039) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1264049 + ... + 1265345.

It is an arithmetic number, because the mean of its divisors is an integer number (63627960).

Almost surely, 2^1640312009 is an apocalyptic number.

1640312009 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1640312009 is a deficient number, since it is larger than the sum of its proper divisors (395782711).

1640312009 is a wasteful number, since it uses less digits than its factorization.

1640312009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1617.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 1640312009 is about 40500.7655359747. The cubic root of 1640312009 is about 1179.3484886199.

The spelling of 1640312009 in words is "one billion, six hundred forty million, three hundred twelve thousand, nine".