1991342663700 has 288 divisors, whose sum is σ = 6365558828160. Its totient is φ = 477628876800.

The previous prime is 1991342663693. The next prime is 1991342663729. The reversal of 1991342663700 is 73662431991.

It is a super-2 number, since 2×1991342663700² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 95 ways as a sum of consecutive naturals, for example, 25416186 + ... + 25494414.

It is an arithmetic number, because the mean of its divisors is an integer number (22102634820).

Almost surely, 2^{1991342663700} is an apocalyptic number.

1991342663700 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 1991342663700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3182779414080).

1991342663700 is an abundant number, since it is smaller than the sum of its proper divisors (4374216164460).

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

1991342663700 is a wasteful number, since it uses less digits than its factorization.

1991342663700 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78427 (or 78420 counting only the distinct ones).

The product of its (nonzero) digits is 1469664, while the sum is 51.

The spelling of 1991342663700 in words is "one trillion, nine hundred ninety-one billion, three hundred forty-two million, six hundred sixty-three thousand, seven hundred".