1664421064 has 8 divisors (see below), whose sum is σ = 3120789510. Its totient is φ = 832210528.

The previous prime is 1664421049. The next prime is 1664421079. The reversal of 1664421064 is 4601244661.

It is an interprime number because it is at equal distance from previous prime (1664421049) and next prime (1664421079).

It can be written as a sum of positive squares in only one way, i.e., 1580698564 + 83722500 = 39758^2 + 9150^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104026309 + ... + 104026324.

Almost surely, 2^1664421064 is an apocalyptic number.

It is an amenable number.

1664421064 is a deficient number, since it is larger than the sum of its proper divisors (1456368446).

1664421064 is a wasteful number, since it uses less digits than its factorization.

1664421064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208052639 (or 208052635 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 34.

The square root of 1664421064 is about 40797.3168725592. The cubic root of 1664421064 is about 1185.0983708921.

The spelling of 1664421064 in words is "one billion, six hundred sixty-four million, four hundred twenty-one thousand, sixty-four".