1691019636 has 12 divisors (see below), whose sum is σ = 3945712512. Its totient is φ = 563673208.

The previous prime is 1691019619. The next prime is 1691019637. The reversal of 1691019636 is 6369101961.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1691019637) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70459140 + ... + 70459163.

It is an arithmetic number, because the mean of its divisors is an integer number (328809376).

Almost surely, 2^1691019636 is an apocalyptic number.

It is an amenable number.

1691019636 is an abundant number, since it is smaller than the sum of its proper divisors (2254692876).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1691019636 is a wasteful number, since it uses less digits than its factorization.

1691019636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140918310 (or 140918308 counting only the distinct ones).

The product of its (nonzero) digits is 52488, while the sum is 42.

The square root of 1691019636 is about 41122.0091435231. The cubic root of 1691019636 is about 1191.3779288346.

The spelling of 1691019636 in words is "one billion, six hundred ninety-one million, nineteen thousand, six hundred thirty-six".