1921517669 has 2 divisors, whose sum is σ = 1921517670. Its totient is φ = 1921517668.

The previous prime is 1921517657. The next prime is 1921517677. The reversal of 1921517669 is 9667151291.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1754772100 + 166745569 = 41890^2 + 12913^2 .

It is a cyclic number.

It is not a de Polignac number, because 1921517669 - 2⁸ = 1921517413 is a prime.

It is a super-2 number, since 2×1921517669² = 7384460304558387122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1921517639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 960758834 + 960758835.

It is an arithmetic number, because the mean of its divisors is an integer number (960758835).

Almost surely, 2^1921517669 is an apocalyptic number.

It is an amenable number.

1921517669 is a deficient number, since it is larger than the sum of its proper divisors (1).

1921517669 is an equidigital number, since it uses as much as digits as its factorization.

1921517669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 204120, while the sum is 47.

The square root of 1921517669 is about 43835.1191283884. The cubic root of 1921517669 is about 1243.2203988031.

The spelling of 1921517669 in words is "one billion, nine hundred twenty-one million, five hundred seventeen thousand, six hundred sixty-nine".