1969778966849 has 4 divisors (see below), whose sum is σ = 1987210639236. Its totient is φ = 1952347294464.

The previous prime is 1969778966843. The next prime is 1969778966893. The reversal of 1969778966849 is 9486698779691.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 181354184449 + 1788424782400 = 425857^2 + 1337320^2 .

It is a cyclic number.

It is not a de Polignac number, because 1969778966849 - 2⁸ = 1969778966593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1969778966843) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8715836024 + ... + 8715836249.

It is an arithmetic number, because the mean of its divisors is an integer number (496802659809).

Almost surely, 2^{1969778966849} is an apocalyptic number.

It is an amenable number.

1969778966849 is a deficient number, since it is larger than the sum of its proper divisors (17431672387).

1969778966849 is a wasteful number, since it uses less digits than its factorization.

1969778966849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17431672386.

The product of its digits is 17777055744, while the sum is 89.

The spelling of 1969778966849 in words is "one trillion, nine hundred sixty-nine billion, seven hundred seventy-eight million, nine hundred sixty-six thousand, eight hundred forty-nine".