1691009091 has 12 divisors (see below), whose sum is σ = 2586249432. Its totient is φ = 1061025216.

The previous prime is 1691009081. The next prime is 1691009093. The reversal of 1691009091 is 1909001961.

It is not a de Polignac number, because 1691009091 - 2⁶ = 1691009027 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1691009093) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5526021 + ... + 5526326.

It is an arithmetic number, because the mean of its divisors is an integer number (215520786).

Almost surely, 2^1691009091 is an apocalyptic number.

1691009091 is a deficient number, since it is larger than the sum of its proper divisors (895240341).

1691009091 is a wasteful number, since it uses less digits than its factorization.

1691009091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11052370 (or 11052367 counting only the distinct ones).

The product of its (nonzero) digits is 4374, while the sum is 36.

The square root of 1691009091 is about 41121.8809273117. The cubic root of 1691009091 is about 1191.3754523985.

The spelling of 1691009091 in words is "one billion, six hundred ninety-one million, nine thousand, ninety-one".