1966938111820 has 384 divisors, whose sum is σ = 4891543437312. Its totient is φ = 657233280000.

The previous prime is 1966938111811. The next prime is 1966938111829. The reversal of 1966938111820 is 281118396691.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1966938111811) and next prime (1966938111829).

It is a Harshad number since it is a multiple of its sum of digits (55).

It is not an unprimeable number, because it can be changed into a prime (1966938111829) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 4954503862 + ... + 4954504258.

It is an arithmetic number, because the mean of its divisors is an integer number (12738394368).

Almost surely, 2^{1966938111820} is an apocalyptic number.

1966938111820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1966938111820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2445771718656).

1966938111820 is an abundant number, since it is smaller than the sum of its proper divisors (2924605325492).

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

1966938111820 is a wasteful number, since it uses less digits than its factorization.

1966938111820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 821 (or 819 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 55.

The spelling of 1966938111820 in words is "one trillion, nine hundred sixty-six billion, nine hundred thirty-eight million, one hundred eleven thousand, eight hundred twenty".