1866464640 has 128 divisors (see below), whose sum is σ = 6610456800. Its totient is φ = 497719296.

The previous prime is 1866464609. The next prime is 1866464653. The reversal of 1866464640 is 464646681.

1866464640 is a `hidden beast` number, since 186 + 6 + 4 + 6 + 464 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36727 + ... + 71286.

Almost surely, 2^1866464640 is an apocalyptic number.

1866464640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1866464640 is an abundant number, since it is smaller than the sum of its proper divisors (4743992160).

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

1866464640 is a wasteful number, since it uses less digits than its factorization.

1866464640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108041 (or 108023 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 45.

The square root of 1866464640 is about 43202.5999217640. The cubic root of 1866464640 is about 1231.2320789304.

The spelling of 1866464640 in words is "one billion, eight hundred sixty-six million, four hundred sixty-four thousand, six hundred forty".