1691923689 has 9 divisors (see below), whose sum is σ = 2444068029. Its totient is φ = 1127866860.

The previous prime is 1691923663. The next prime is 1691923693. The reversal of 1691923689 is 9863291961.

The square root of 1691923689 is 41133.

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

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 1691923689 - 2²³ = 1683535081 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1691123689) 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, 116544 + ... + 130254.

Almost surely, 2^1691923689 is an apocalyptic number.

1691923689 is the 41133-rd square number.

1691923689 is the 20567-th centered octagonal number.

It is an amenable number.

1691923689 is a deficient number, since it is larger than the sum of its proper divisors (752144340).

1691923689 is an frugal number, since it uses more digits than its factorization.

1691923689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27428 (or 13714 counting only the distinct ones).

The product of its digits is 1259712, while the sum is 54.

The cubic root of 1691923689 is about 1191.5902025192.

The spelling of 1691923689 in words is "one billion, six hundred ninety-one million, nine hundred twenty-three thousand, six hundred eighty-nine".