1664889206 has 4 divisors (see below), whose sum is σ = 2497333812. Its totient is φ = 832444602.

The previous prime is 1664889167. The next prime is 1664889211. The reversal of 1664889206 is 6029884661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6029884661 = 151 ⋅39933011.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 416222300 + ... + 416222303.

It is an arithmetic number, because the mean of its divisors is an integer number (624333453).

Almost surely, 2^1664889206 is an apocalyptic number.

1664889206 is a deficient number, since it is larger than the sum of its proper divisors (832444606).

1664889206 is an equidigital number, since it uses as much as digits as its factorization.

1664889206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 832444605.

The product of its (nonzero) digits is 995328, while the sum is 50.

The square root of 1664889206 is about 40803.0538808065. The cubic root of 1664889206 is about 1185.2094690445.

The spelling of 1664889206 in words is "one billion, six hundred sixty-four million, eight hundred eighty-nine thousand, two hundred six".