1866513369616 has 135 divisors (see below), whose sum is σ = 4284488256879. Its totient is φ = 785425214784.

The previous prime is 1866513369613. The next prime is 1866513369641. The reversal of 1866513369616 is 6169633156681.

The square root of 1866513369616 is 1366204.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1866513369613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 2256968595 + ... + 2256969421.

Almost surely, 2^{1866513369616} is an apocalyptic number.

1866513369616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

1866513369616 is the 1366204-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1866513369616

1866513369616 is an abundant number, since it is smaller than the sum of its proper divisors (2417974887263).

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

1866513369616 is an frugal number, since it uses more digits than its factorization.

1866513369616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1794 (or 895 counting only the distinct ones).

The product of its digits is 25194240, while the sum is 61.

It can be divided in two parts, 18665 and 13369616, that added together give a square (13388281 = 3659²).

The spelling of 1866513369616 in words is "one trillion, eight hundred sixty-six billion, five hundred thirteen million, three hundred sixty-nine thousand, six hundred sixteen".