1340721881 has 8 divisors (see below), whose sum is σ = 1468539720. Its totient is φ = 1218343168.

The previous prime is 1340721803. The next prime is 1340721901. The reversal of 1340721881 is 1881270431.

It can be written as a sum of positive squares in 4 ways, for example, as 801739225 + 538982656 = 28315^2 + 23216^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1340721881 - 2¹⁸ = 1340459737 is a prime.

It is a super-2 number, since 2×1340721881² = 3595070324384356322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1340781881) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 1359266 + ... + 1360251.

It is an arithmetic number, because the mean of its divisors is an integer number (183567465).

Almost surely, 2^1340721881 is an apocalyptic number.

It is an amenable number.

1340721881 is a deficient number, since it is larger than the sum of its proper divisors (127817839).

1340721881 is a wasteful number, since it uses less digits than its factorization.

1340721881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2719563.

The product of its (nonzero) digits is 10752, while the sum is 35.

The square root of 1340721881 is about 36615.8692509136. The cubic root of 1340721881 is about 1102.6717097576.

The spelling of 1340721881 in words is "one billion, three hundred forty million, seven hundred twenty-one thousand, eight hundred eighty-one".