1691975097 has 6 divisors (see below), whose sum is σ = 2443964042. Its totient is φ = 1127983392.

The previous prime is 1691975081. The next prime is 1691975111. The reversal of 1691975097 is 7905791961.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1629817641 + 62157456 = 40371^2 + 7884^2 .

It is not a de Polignac number, because 1691975097 - 2⁴ = 1691975081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1691975297) 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 in 5 ways as a sum of consecutive naturals, for example, 93998608 + ... + 93998625.

Almost surely, 2^1691975097 is an apocalyptic number.

It is an amenable number.

1691975097 is a deficient number, since it is larger than the sum of its proper divisors (751988945).

1691975097 is a wasteful number, since it uses less digits than its factorization.

1691975097 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187997239 (or 187997236 counting only the distinct ones).

The product of its (nonzero) digits is 1071630, while the sum is 54.

The square root of 1691975097 is about 41133.6248949688. The cubic root of 1691975097 is about 1191.6022709612.

The spelling of 1691975097 in words is "one billion, six hundred ninety-one million, nine hundred seventy-five thousand, ninety-seven".