1691666604 has 36 divisors (see below), whose sum is σ = 4277529984. Its totient is φ = 563707872.

The previous prime is 1691666597. The next prime is 1691666609. The reversal of 1691666604 is 4066661961.

It is a tau number, because it is divible by the number of its divisors (36).

It is a self number, because there is not a number n which added to its sum of digits gives 1691666604.

It is not an unprimeable number, because it can be changed into a prime (1691666609) 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, 152949 + ... + 163635.

Almost surely, 2^1691666604 is an apocalyptic number.

It is an amenable number.

1691666604 is an abundant number, since it is smaller than the sum of its proper divisors (2585863380).

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

1691666604 is a wasteful number, since it uses less digits than its factorization.

1691666604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15094 (or 15089 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 45.

The square root of 1691666604 is about 41129.8748356958. The cubic root of 1691666604 is about 1191.5298460768.

The spelling of 1691666604 in words is "one billion, six hundred ninety-one million, six hundred sixty-six thousand, six hundred four".