21651594196 has 12 divisors (see below), whose sum is σ = 40119130548. Its totient is φ = 10188985472.

The previous prime is 21651594163. The next prime is 21651594269. The reversal of 21651594196 is 69149515612.

It can be written as a sum of positive squares in 2 ways, for example, as 18862275600 + 2789318596 = 137340^2 + 52814^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 159202831 + ... + 159202966.

It is an arithmetic number, because the mean of its divisors is an integer number (3343260879).

Almost surely, 2^21651594196 is an apocalyptic number.

It is an amenable number.

21651594196 is a deficient number, since it is larger than the sum of its proper divisors (18467536352).

21651594196 is a wasteful number, since it uses less digits than its factorization.

21651594196 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318405818 (or 318405816 counting only the distinct ones).

The product of its digits is 583200, while the sum is 49.

The spelling of 21651594196 in words is "twenty-one billion, six hundred fifty-one million, five hundred ninety-four thousand, one hundred ninety-six".