1640932805 has 4 divisors (see below), whose sum is σ = 1969119372. Its totient is φ = 1312746240.

The previous prime is 1640932751. The next prime is 1640932823. The reversal of 1640932805 is 5082390461.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5082390461 = 43 ⋅118195127.

It can be written as a sum of positive squares in 2 ways, for example, as 254785444 + 1386147361 = 15962^2 + 37231^2 .

It is not a de Polignac number, because 1640932805 - 2²⁰ = 1639884229 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 164093276 + ... + 164093285.

It is an arithmetic number, because the mean of its divisors is an integer number (492279843).

Almost surely, 2^1640932805 is an apocalyptic number.

It is an amenable number.

1640932805 is a deficient number, since it is larger than the sum of its proper divisors (328186567).

1640932805 is an equidigital number, since it uses as much as digits as its factorization.

1640932805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328186566.

The product of its (nonzero) digits is 51840, while the sum is 38.

The square root of 1640932805 is about 40508.4288142604. The cubic root of 1640932805 is about 1179.4972494406.

The spelling of 1640932805 in words is "one billion, six hundred forty million, nine hundred thirty-two thousand, eight hundred five".