1664056899 has 8 divisors (see below), whose sum is σ = 2465269520. Its totient is φ = 1109371248.

The previous prime is 1664056861. The next prime is 1664056909. The reversal of 1664056899 is 9986504661.

It is a happy number.

1664056899 is a `hidden beast` number, since 16 + 64 + 0 + 568 + 9 + 9 = 666.

It is not a de Polignac number, because 1664056899 - 2¹¹ = 1664054851 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1664056399) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30815842 + ... + 30815895.

It is an arithmetic number, because the mean of its divisors is an integer number (308158690).

Almost surely, 2^1664056899 is an apocalyptic number.

1664056899 is a deficient number, since it is larger than the sum of its proper divisors (801212621).

1664056899 is an equidigital number, since it uses as much as digits as its factorization.

1664056899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61631746 (or 61631740 counting only the distinct ones).

The product of its (nonzero) digits is 2799360, while the sum is 54.

The square root of 1664056899 is about 40792.8535285287. The cubic root of 1664056899 is about 1185.0119338648.

The spelling of 1664056899 in words is "one billion, six hundred sixty-four million, fifty-six thousand, eight hundred ninety-nine".