1642691605 has 8 divisors (see below), whose sum is σ = 1991552472. Its totient is φ = 1300604928.

The previous prime is 1642691599. The next prime is 1642691653. The reversal of 1642691605 is 5061962461.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 267616881 + 1375074724 = 16359^2 + 37082^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1642691605 - 2³ = 1642691597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1693012 + ... + 1693981.

It is an arithmetic number, because the mean of its divisors is an integer number (248944059).

Almost surely, 2^1642691605 is an apocalyptic number.

It is an amenable number.

1642691605 is a deficient number, since it is larger than the sum of its proper divisors (348860867).

1642691605 is an equidigital number, since it uses as much as digits as its factorization.

1642691605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3387095.

The product of its (nonzero) digits is 77760, while the sum is 40.

The square root of 1642691605 is about 40530.1320624545. The cubic root of 1642691605 is about 1179.9185055756.

The spelling of 1642691605 in words is "one billion, six hundred forty-two million, six hundred ninety-one thousand, six hundred five".