1968321881 has 4 divisors (see below), whose sum is σ = 1982689332. Its totient is φ = 1953954432.

The previous prime is 1968321857. The next prime is 1968321889. The reversal of 1968321881 is 1881238691.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 969761881 + 998560000 = 31141^2 + 31600^2 .

It is a cyclic number.

It is not a de Polignac number, because 1968321881 - 2²² = 1964127577 is a prime.

It is a super-2 number, since 2×1968321881² = 7748582054446756322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1968321889) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7183520 + ... + 7183793.

It is an arithmetic number, because the mean of its divisors is an integer number (495672333).

Almost surely, 2^1968321881 is an apocalyptic number.

It is an amenable number.

1968321881 is a deficient number, since it is larger than the sum of its proper divisors (14367451).

1968321881 is a wasteful number, since it uses less digits than its factorization.

1968321881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14367450.

The product of its digits is 165888, while the sum is 47.

The square root of 1968321881 is about 44365.7737563541. The cubic root of 1968321881 is about 1253.2336289817.

The spelling of 1968321881 in words is "one billion, nine hundred sixty-eight million, three hundred twenty-one thousand, eight hundred eighty-one".