1664664655 has 4 divisors (see below), whose sum is σ = 1997597592. Its totient is φ = 1331731720.

The previous prime is 1664664643. The next prime is 1664664671. The reversal of 1664664655 is 5564664661.

It is a happy number.

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

It is not a de Polignac number, because 1664664655 - 2⁹ = 1664664143 is a prime.

It is a super-2 number, since 2×1664664655² = 5542216827212538050, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1664664599 and 1664664608.

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, 166466461 + ... + 166466470.

It is an arithmetic number, because the mean of its divisors is an integer number (499399398).

Almost surely, 2^1664664655 is an apocalyptic number.

1664664655 is a deficient number, since it is larger than the sum of its proper divisors (332932937).

1664664655 is an equidigital number, since it uses as much as digits as its factorization.

1664664655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332932936.

The product of its digits is 3110400, while the sum is 49.

The square root of 1664664655 is about 40800.3021434891. The cubic root of 1664664655 is about 1185.1561818274.

The spelling of 1664664655 in words is "one billion, six hundred sixty-four million, six hundred sixty-four thousand, six hundred fifty-five".