1866821946 has 16 divisors (see below), whose sum is σ = 4073066208. Its totient is φ = 565703600.

The previous prime is 1866821941. The next prime is 1866821987. The reversal of 1866821946 is 6491286681.

It is not an unprimeable number, because it can be changed into a prime (1866821941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14142525 + ... + 14142656.

It is an arithmetic number, because the mean of its divisors is an integer number (254566638).

Almost surely, 2^1866821946 is an apocalyptic number.

1866821946 is an abundant number, since it is smaller than the sum of its proper divisors (2206244262).

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

1866821946 is a wasteful number, since it uses less digits than its factorization.

1866821946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28285197.

The product of its digits is 995328, while the sum is 51.

The square root of 1866821946 is about 43206.7349611146. The cubic root of 1866821946 is about 1231.3106407437.

The spelling of 1866821946 in words is "one billion, eight hundred sixty-six million, eight hundred twenty-one thousand, nine hundred forty-six".