1640566939 has 8 divisors (see below), whose sum is σ = 1838080368. Its totient is φ = 1451115360.

The previous prime is 1640566927. The next prime is 1640566943. The reversal of 1640566939 is 9396650461.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1640566939 - 2¹⁵ = 1640534171 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1640566892 and 1640566901.

It is not an unprimeable number, because it can be changed into a prime (1640566969) 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 7 ways as a sum of consecutive naturals, for example, 2015032 + ... + 2015845.

It is an arithmetic number, because the mean of its divisors is an integer number (229760046).

Almost surely, 2^1640566939 is an apocalyptic number.

1640566939 is a deficient number, since it is larger than the sum of its proper divisors (197513429).

1640566939 is a wasteful number, since it uses less digits than its factorization.

1640566939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4030925.

The product of its (nonzero) digits is 1049760, while the sum is 49.

The square root of 1640566939 is about 40503.9126381637. The cubic root of 1640566939 is about 1179.4095818214.

The spelling of 1640566939 in words is "one billion, six hundred forty million, five hundred sixty-six thousand, nine hundred thirty-nine".