1381121940 has 192 divisors, whose sum is σ = 4522936320. Its totient is φ = 311477760.

The previous prime is 1381121921. The next prime is 1381121947. The reversal of 1381121940 is 491211831.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 1381121898 and 1381121907.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1381121947) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 560431 + ... + 562889.

It is an arithmetic number, because the mean of its divisors is an integer number (23556960).

Almost surely, 2^1381121940 is an apocalyptic number.

1381121940 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 1381121940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2261468160).

1381121940 is an abundant number, since it is smaller than the sum of its proper divisors (3141814380).

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

1381121940 is a wasteful number, since it uses less digits than its factorization.

1381121940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2542 (or 2540 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 30.

The square root of 1381121940 is about 37163.4489788017. The cubic root of 1381121940 is about 1113.6379139256.

It can be divided in two parts, 1381 and 121940, that added together give a palindrome (123321).

The spelling of 1381121940 in words is "one billion, three hundred eighty-one million, one hundred twenty-one thousand, nine hundred forty".