1820405668 has 6 divisors (see below), whose sum is σ = 3185709926. Its totient is φ = 910202832.

The previous prime is 1820405651. The next prime is 1820405687. The reversal of 1820405668 is 8665040281.

It can be written as a sum of positive squares in only one way, i.e., 1276489984 + 543915684 = 35728^2 + 23322^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1820405668.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 227550705 + ... + 227550712.

Almost surely, 2^1820405668 is an apocalyptic number.

It is an amenable number.

1820405668 is a deficient number, since it is larger than the sum of its proper divisors (1365304258).

1820405668 is a wasteful number, since it uses less digits than its factorization.

1820405668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 455101421 (or 455101419 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 40.

The square root of 1820405668 is about 42666.2122527885. The cubic root of 1820405668 is about 1221.0198558075.

The spelling of 1820405668 in words is "one billion, eight hundred twenty million, four hundred five thousand, six hundred sixty-eight".