1691868128 has 24 divisors (see below), whose sum is σ = 3339677880. Its totient is φ = 843696000.

The previous prime is 1691868103. The next prime is 1691868131. The reversal of 1691868128 is 8218681961.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57623 + ... + 81878.

It is an arithmetic number, because the mean of its divisors is an integer number (139153245).

Almost surely, 2^1691868128 is an apocalyptic number.

It is an amenable number.

1691868128 is a deficient number, since it is larger than the sum of its proper divisors (1647809752).

1691868128 is a wasteful number, since it uses less digits than its factorization.

1691868128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139890 (or 139882 counting only the distinct ones).

The product of its digits is 331776, while the sum is 50.

The square root of 1691868128 is about 41132.3246121587. The cubic root of 1691868128 is about 1191.5771588522.

The spelling of 1691868128 in words is "one billion, six hundred ninety-one million, eight hundred sixty-eight thousand, one hundred twenty-eight".