11931381000 has 640 divisors, whose sum is σ = 52025276160. Its totient is φ = 2477952000.

The previous prime is 11931380927. The next prime is 11931381001. The reversal of 11931381000 is 18313911.

It is a happy number.

It is a super-2 number, since 2×11931381000² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (11931381001) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 6236044 + ... + 6237956.

It is an arithmetic number, because the mean of its divisors is an integer number (81289494).

Almost surely, 2^11931381000 is an apocalyptic number.

11931381000 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 11931381000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26012638080).

11931381000 is an abundant number, since it is smaller than the sum of its proper divisors (40093895160).

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

11931381000 is a wasteful number, since it uses less digits than its factorization.

11931381000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1964 (or 1941 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

Adding to 11931381000 its reverse (18313911), we get a palindrome (11949694911).

The spelling of 11931381000 in words is "eleven billion, nine hundred thirty-one million, three hundred eighty-one thousand".