1027991667 has 4 divisors (see below), whose sum is σ = 1370655560. Its totient is φ = 685327776.

The previous prime is 1027991659. The next prime is 1027991707. The reversal of 1027991667 is 7661997201.

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: 7661997201 = 3 ⋅2553999067.

It is not a de Polignac number, because 1027991667 - 2³ = 1027991659 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1027993667) 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, 171331942 + ... + 171331947.

It is an arithmetic number, because the mean of its divisors is an integer number (342663890).

Almost surely, 2^1027991667 is an apocalyptic number.

1027991667 is a deficient number, since it is larger than the sum of its proper divisors (342663893).

1027991667 is an equidigital number, since it uses as much as digits as its factorization.

1027991667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342663892.

The product of its (nonzero) digits is 285768, while the sum is 48.

The square root of 1027991667 is about 32062.3091339348. The cubic root of 1027991667 is about 1009.2448254931.

The spelling of 1027991667 in words is "one billion, twenty-seven million, nine hundred ninety-one thousand, six hundred sixty-seven".