1921629617 has 2 divisors, whose sum is σ = 1921629618. Its totient is φ = 1921629616.

The previous prime is 1921629571. The next prime is 1921629637. The reversal of 1921629617 is 7169261291.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1030666816 + 890962801 = 32104^2 + 29849^2 .

It is an emirp because it is prime and its reverse (7169261291) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1921629617 - 2⁸ = 1921629361 is a prime.

It is not a weakly prime, because it can be changed into another prime (1921629637) 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 as a sum of consecutive naturals, namely, 960814808 + 960814809.

It is an arithmetic number, because the mean of its divisors is an integer number (960814809).

Almost surely, 2^1921629617 is an apocalyptic number.

It is an amenable number.

1921629617 is a deficient number, since it is larger than the sum of its proper divisors (1).

1921629617 is an equidigital number, since it uses as much as digits as its factorization.

1921629617 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81648, while the sum is 44.

The square root of 1921629617 is about 43836.3960311520. The cubic root of 1921629617 is about 1243.2445417564.

The spelling of 1921629617 in words is "one billion, nine hundred twenty-one million, six hundred twenty-nine thousand, six hundred seventeen".