1691953568 has 12 divisors (see below), whose sum is σ = 3331033650. Its totient is φ = 845976768.

The previous prime is 1691953567. The next prime is 1691953573. The reversal of 1691953568 is 8653591961.

It can be written as a sum of positive squares in only one way, i.e., 1650634384 + 41319184 = 40628^2 + 6428^2 .

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (1691953567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 26436743 + ... + 26436806.

Almost surely, 2^1691953568 is an apocalyptic number.

It is an amenable number.

1691953568 is a deficient number, since it is larger than the sum of its proper divisors (1639080082).

1691953568 is an equidigital number, since it uses as much as digits as its factorization.

1691953568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52873559 (or 52873551 counting only the distinct ones).

The product of its digits is 1749600, while the sum is 53.

The square root of 1691953568 is about 41133.3631982604. The cubic root of 1691953568 is about 1191.5972168849.

The spelling of 1691953568 in words is "one billion, six hundred ninety-one million, nine hundred fifty-three thousand, five hundred sixty-eight".