1091311863840 has 768 divisors, whose sum is σ = 4419808727040. Its totient is φ = 248554045440.

The previous prime is 1091311863827. The next prime is 1091311863871. The reversal of 1091311863840 is 483681131901.

1091311863840 is a `hidden beast` number, since 1 + 0 + 9 + 1 + 3 + 1 + 1 + 8 + 638 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 716553319 + ... + 716554841.

It is an arithmetic number, because the mean of its divisors is an integer number (5754959280).

Almost surely, 2^{1091311863840} is an apocalyptic number.

1091311863840 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 1091311863840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2209904363520).

1091311863840 is an abundant number, since it is smaller than the sum of its proper divisors (3328496863200).

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

1091311863840 is a wasteful number, since it uses less digits than its factorization.

1091311863840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2462 (or 2448 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The spelling of 1091311863840 in words is "one trillion, ninety-one billion, three hundred eleven million, eight hundred sixty-three thousand, eight hundred forty".