1866491644 has 6 divisors (see below), whose sum is σ = 3266360384. Its totient is φ = 933245820.

The previous prime is 1866491621. The next prime is 1866491663. The reversal of 1866491644 is 4461946681.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 233311452 + ... + 233311459.

Almost surely, 2^1866491644 is an apocalyptic number.

It is an amenable number.

1866491644 is a deficient number, since it is larger than the sum of its proper divisors (1399868740).

1866491644 is a wasteful number, since it uses less digits than its factorization.

1866491644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 466622915 (or 466622913 counting only the distinct ones).

The product of its digits is 995328, while the sum is 49.

The square root of 1866491644 is about 43202.9124481209. The cubic root of 1866491644 is about 1231.2380167214.

The spelling of 1866491644 in words is "one billion, eight hundred sixty-six million, four hundred ninety-one thousand, six hundred forty-four".