1664986005 has 12 divisors (see below), whose sum is σ = 2885975820. Its totient is φ = 887992512.

The previous prime is 1664986003. The next prime is 1664986021. The reversal of 1664986005 is 5006894661.

It can be written as a sum of positive squares in 2 ways, for example, as 673869681 + 991116324 = 25959^2 + 31482^2 .

It is not a de Polignac number, because 1664986005 - 2¹ = 1664986003 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 36999689 = 1664986005 / (1 + 6 + 6 + 4 + 9 + 8 + 6 + 0 + 0 + 5).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664986003) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18499800 + ... + 18499889.

It is an arithmetic number, because the mean of its divisors is an integer number (240497985).

Almost surely, 2^1664986005 is an apocalyptic number.

1664986005 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1664986005 is a deficient number, since it is larger than the sum of its proper divisors (1220989815).

1664986005 is a wasteful number, since it uses less digits than its factorization.

1664986005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36999700 (or 36999697 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The square root of 1664986005 is about 40804.2400370354. The cubic root of 1664986005 is about 1185.2324385145.

The spelling of 1664986005 in words is "one billion, six hundred sixty-four million, nine hundred eighty-six thousand, five".