1691968773049 has 9 divisors (see below), whose sum is σ = 1696404224613. Its totient is φ = 1687544898492.

The previous prime is 1691968773037. The next prime is 1691968773107. The reversal of 1691968773049 is 9403778691961.

The square root of 1691968773049 is 1300757.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 1691968773049 - 2⁵ = 1691968773017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1691968773149) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 571030842 + ... + 571033804.

Almost surely, 2^{1691968773049} is an apocalyptic number.

1691968773049 is the 1300757-th square number.

1691968773049 is the 650379-th centered octagonal number.

It is an amenable number.

1691968773049 is a deficient number, since it is larger than the sum of its proper divisors (4435451564).

1691968773049 is an frugal number, since it uses more digits than its factorization.

1691968773049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6804 (or 3402 counting only the distinct ones).

The product of its (nonzero) digits is 123451776, while the sum is 70.

The spelling of 1691968773049 in words is "one trillion, six hundred ninety-one billion, nine hundred sixty-eight million, seven hundred seventy-three thousand, forty-nine".