1664459149 has 4 divisors (see below), whose sum is σ = 1667447964. Its totient is φ = 1661470336.

The previous prime is 1664459141. The next prime is 1664459191. The reversal of 1664459149 is 9419544661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9419544661 = 127 ⋅74169643.

It can be written as a sum of positive squares in 2 ways, for example, as 431185225 + 1233273924 = 20765^2 + 35118^2 .

It is a cyclic number.

It is not a de Polignac number, because 1664459149 - 2³ = 1664459141 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664459141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1493572 + ... + 1494685.

It is an arithmetic number, because the mean of its divisors is an integer number (416861991).

Almost surely, 2^1664459149 is an apocalyptic number.

It is an amenable number.

1664459149 is a deficient number, since it is larger than the sum of its proper divisors (2988815).

1664459149 is an equidigital number, since it uses as much as digits as its factorization.

1664459149 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2988814.

The product of its digits is 933120, while the sum is 49.

The square root of 1664459149 is about 40797.7836285257. The cubic root of 1664459149 is about 1185.1074098964.

The spelling of 1664459149 in words is "one billion, six hundred sixty-four million, four hundred fifty-nine thousand, one hundred forty-nine".