21980865838 has 8 divisors (see below), whose sum is σ = 32974170840. Its totient is φ = 10989475560.

The previous prime is 21980865833. The next prime is 21980865899. The reversal of 21980865838 is 83856808912.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21980865833) 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, 449628 + ... + 496111.

It is an arithmetic number, because the mean of its divisors is an integer number (4121771355).

Almost surely, 2^21980865838 is an apocalyptic number.

21980865838 is a deficient number, since it is larger than the sum of its proper divisors (10993305002).

21980865838 is a wasteful number, since it uses less digits than its factorization.

21980865838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 957362.

The product of its (nonzero) digits is 6635520, while the sum is 58.

The spelling of 21980865838 in words is "twenty-one billion, nine hundred eighty million, eight hundred sixty-five thousand, eight hundred thirty-eight".