1664151409 has 4 divisors (see below), whose sum is σ = 1664308800. Its totient is φ = 1663994020.

The previous prime is 1664151397. The next prime is 1664151421. The reversal of 1664151409 is 9041514661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9041514661 = 1171 ⋅7721191.

It is an interprime number because it is at equal distance from previous prime (1664151397) and next prime (1664151421).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1664151409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1664151439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61597 + ... + 84394.

It is an arithmetic number, because the mean of its divisors is an integer number (416077200).

Almost surely, 2^1664151409 is an apocalyptic number.

It is an amenable number.

1664151409 is a deficient number, since it is larger than the sum of its proper divisors (157391).

1664151409 is a wasteful number, since it uses less digits than its factorization.

1664151409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157390.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 1664151409 is about 40794.0119257717. The cubic root of 1664151409 is about 1185.0343676645.

The spelling of 1664151409 in words is "one billion, six hundred sixty-four million, one hundred fifty-one thousand, four hundred nine".