1665406242 has 24 divisors (see below), whose sum is σ = 3724780800. Its totient is φ = 537227640.

The previous prime is 1665406217. The next prime is 1665406291. The reversal of 1665406242 is 2426045661.

1665406242 is a `hidden beast` number, since 1 + 6 + 6 + 5 + 406 + 242 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 1665406197 and 1665406206.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1491742 + ... + 1492857.

It is an arithmetic number, because the mean of its divisors is an integer number (155199200).

Almost surely, 2^1665406242 is an apocalyptic number.

1665406242 is an abundant number, since it is smaller than the sum of its proper divisors (2059374558).

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

1665406242 is a wasteful number, since it uses less digits than its factorization.

1665406242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2984638 (or 2984635 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The square root of 1665406242 is about 40809.3891402457. The cubic root of 1665406242 is about 1185.3321463848.

The spelling of 1665406242 in words is "one billion, six hundred sixty-five million, four hundred six thousand, two hundred forty-two".