1664385279 has 16 divisors (see below), whose sum is σ = 2236416000. Its totient is φ = 1100988576.

The previous prime is 1664385259. The next prime is 1664385301. The reversal of 1664385279 is 9725834661.

It is not a de Polignac number, because 1664385279 - 2¹³ = 1664377087 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664385259) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 742242 + ... + 744480.

It is an arithmetic number, because the mean of its divisors is an integer number (139776000).

Almost surely, 2^1664385279 is an apocalyptic number.

1664385279 is a deficient number, since it is larger than the sum of its proper divisors (572030721).

1664385279 is a wasteful number, since it uses less digits than its factorization.

1664385279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4054.

The product of its digits is 2177280, while the sum is 51.

The square root of 1664385279 is about 40796.8782996935. The cubic root of 1664385279 is about 1185.0898776388.

The spelling of 1664385279 in words is "one billion, six hundred sixty-four million, three hundred eighty-five thousand, two hundred seventy-nine".