1989653969 has 2 divisors, whose sum is σ = 1989653970. Its totient is φ = 1989653968.

The previous prime is 1989653891. The next prime is 1989653983. The reversal of 1989653969 is 9693569891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1623122944 + 366531025 = 40288^2 + 19145^2 .

It is a cyclic number.

It is not a de Polignac number, because 1989653969 - 2⁸ = 1989653713 is a prime.

It is a super-2 number, since 2×1989653969² = 7917445832714905922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1989653669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 994826984 + 994826985.

It is an arithmetic number, because the mean of its divisors is an integer number (994826985).

Almost surely, 2^1989653969 is an apocalyptic number.

It is an amenable number.

1989653969 is a deficient number, since it is larger than the sum of its proper divisors (1).

1989653969 is an equidigital number, since it uses as much as digits as its factorization.

1989653969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 28343520, while the sum is 65.

The square root of 1989653969 is about 44605.5374253018. The cubic root of 1989653969 is about 1257.7447625404.

The spelling of 1989653969 in words is "one billion, nine hundred eighty-nine million, six hundred fifty-three thousand, nine hundred sixty-nine".