1865644012 has 24 divisors (see below), whose sum is σ = 3304543536. Its totient is φ = 921543168.

The previous prime is 1865643973. The next prime is 1865644019. The reversal of 1865644012 is 2104465681.

It is a super-2 number, since 2×1865644012² = 6961255159022912288, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1865644019) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 134883 + ... + 148069.

It is an arithmetic number, because the mean of its divisors is an integer number (137689314).

Almost surely, 2^1865644012 is an apocalyptic number.

It is an amenable number.

1865644012 is a deficient number, since it is larger than the sum of its proper divisors (1438899524).

1865644012 is a wasteful number, since it uses less digits than its factorization.

1865644012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13617 (or 13615 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 37.

The square root of 1865644012 is about 43193.1014399290. The cubic root of 1865644012 is about 1231.0516073209.

The spelling of 1865644012 in words is "one billion, eight hundred sixty-five million, six hundred forty-four thousand, twelve".