1640879699 has 4 divisors (see below), whose sum is σ = 1679039736. Its totient is φ = 1602719664.

The previous prime is 1640879683. The next prime is 1640879707. The reversal of 1640879699 is 9969780461.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1640879699 - 2⁴ = 1640879683 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1640879609) 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 3 ways as a sum of consecutive naturals, for example, 19079954 + ... + 19080039.

It is an arithmetic number, because the mean of its divisors is an integer number (419759934).

Almost surely, 2^1640879699 is an apocalyptic number.

1640879699 is a deficient number, since it is larger than the sum of its proper divisors (38160037).

1640879699 is an equidigital number, since it uses as much as digits as its factorization.

1640879699 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38160036.

The product of its (nonzero) digits is 5878656, while the sum is 59.

The square root of 1640879699 is about 40507.7733157477. The cubic root of 1640879699 is about 1179.4845251624.

The spelling of 1640879699 in words is "one billion, six hundred forty million, eight hundred seventy-nine thousand, six hundred ninety-nine".