968638021 has 4 divisors (see below), whose sum is σ = 1043148652. Its totient is φ = 894127392.

The previous prime is 968638007. The next prime is 968638037. The reversal of 968638021 is 120836869.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 120836869 = 599 ⋅201731.

It can be written as a sum of positive squares in 2 ways, for example, as 560032225 + 408605796 = 23665^2 + 20214^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-968638021 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (968438021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37255296 + ... + 37255321.

It is an arithmetic number, because the mean of its divisors is an integer number (260787163).

Almost surely, 2^968638021 is an apocalyptic number.

It is an amenable number.

968638021 is a deficient number, since it is larger than the sum of its proper divisors (74510631).

968638021 is a wasteful number, since it uses less digits than its factorization.

968638021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74510630.

The product of its (nonzero) digits is 124416, while the sum is 43.

The square root of 968638021 is about 31122.9500690407. The cubic root of 968638021 is about 989.4347761558.

The spelling of 968638021 in words is "nine hundred sixty-eight million, six hundred thirty-eight thousand, twenty-one".