1866138673440 has 96 divisors (see below), whose sum is σ = 5899558674240. Its totient is φ = 495840420864.

The previous prime is 1866138673393. The next prime is 1866138673453. The reversal of 1866138673440 is 443768316681.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×1866138673440² (a number of 25 digits) contains 22 as substring.

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 in 15 ways as a sum of consecutive naturals, for example, 6884710 + ... + 7150629.

It is an arithmetic number, because the mean of its divisors is an integer number (61453736190).

Almost surely, 2^{1866138673440} is an apocalyptic number.

1866138673440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1866138673440 is an abundant number, since it is smaller than the sum of its proper divisors (4033420000800).

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

1866138673440 is a wasteful number, since it uses less digits than its factorization.

1866138673440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14035634 (or 14035626 counting only the distinct ones).

The product of its (nonzero) digits is 13934592, while the sum is 57.

The spelling of 1866138673440 in words is "one trillion, eight hundred sixty-six billion, one hundred thirty-eight million, six hundred seventy-three thousand, four hundred forty".