1311161021100 has 360 divisors, whose sum is σ = 4975930040928. Its totient is φ = 292383820800.

The previous prime is 1311161021081. The next prime is 1311161021117. The reversal of 1311161021100 is 11201611131.

1311161021100 is a `hidden beast` number, since 1 + 31 + 1 + 1 + 610 + 21 + 1 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

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 119 ways as a sum of consecutive naturals, for example, 2042694 + ... + 2606706.

Almost surely, 2^{1311161021100} is an apocalyptic number.

1311161021100 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 1311161021100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2487965020464).

1311161021100 is an abundant number, since it is smaller than the sum of its proper divisors (3664769019828).

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

1311161021100 is a wasteful number, since it uses less digits than its factorization.

1311161021100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 564087 (or 564071 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 18.

Adding to 1311161021100 its reverse (11201611131), we get a palindrome (1322362632231).

The spelling of 1311161021100 in words is "one trillion, three hundred eleven billion, one hundred sixty-one million, twenty-one thousand, one hundred".