1921559489 has 2 divisors, whose sum is σ = 1921559490. Its totient is φ = 1921559488.

The previous prime is 1921559413. The next prime is 1921559527. The reversal of 1921559489 is 9849551291.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1800559489 + 121000000 = 42433^2 + 11000^2 .

It is a cyclic number.

It is not a de Polignac number, because 1921559489 - 2²⁴ = 1904782273 is a prime.

It is a super-2 number, since 2×1921559489² = 7384781739531882242, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1921559489.

It is not a weakly prime, because it can be changed into another prime (1921559789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 960779744 + 960779745.

It is an arithmetic number, because the mean of its divisors is an integer number (960779745).

Almost surely, 2^1921559489 is an apocalyptic number.

It is an amenable number.

1921559489 is a deficient number, since it is larger than the sum of its proper divisors (1).

1921559489 is an equidigital number, since it uses as much as digits as its factorization.

1921559489 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1166400, while the sum is 53.

The square root of 1921559489 is about 43835.5961405796. The cubic root of 1921559489 is about 1243.2294179065.

The spelling of 1921559489 in words is "one billion, nine hundred twenty-one million, five hundred fifty-nine thousand, four hundred eighty-nine".