1671221917 has 4 divisors (see below), whose sum is σ = 1702754460. Its totient is φ = 1639689376.

The previous prime is 1671221891. The next prime is 1671221953. The reversal of 1671221917 is 7191221761.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7191221761 = 103 ⋅69817687.

It can be written as a sum of positive squares in 2 ways, for example, as 1365006916 + 306215001 = 36946^2 + 17499^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1671221917 is a prime.

It is a super-2 number, since 2×1671221917² = 5585965391722309778, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1671221117) 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, 15766192 + ... + 15766297.

It is an arithmetic number, because the mean of its divisors is an integer number (425688615).

Almost surely, 2^1671221917 is an apocalyptic number.

It is an amenable number.

1671221917 is a deficient number, since it is larger than the sum of its proper divisors (31532543).

1671221917 is an equidigital number, since it uses as much as digits as its factorization.

1671221917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31532542.

The product of its digits is 10584, while the sum is 37.

The square root of 1671221917 is about 40880.5811724833. The cubic root of 1671221917 is about 1186.7102881940.

The spelling of 1671221917 in words is "one billion, six hundred seventy-one million, two hundred twenty-one thousand, nine hundred seventeen".