21533273138 has 8 divisors (see below), whose sum is σ = 34784518188. Its totient is φ = 9938433744.

The previous prime is 21533273137. The next prime is 21533273189. The reversal of 21533273138 is 83137233512.

It can be written as a sum of positive squares in 2 ways, for example, as 21285934609 + 247338529 = 145897^2 + 15727^2 .

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21533273131) 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, 414101381 + ... + 414101432.

Almost surely, 2^21533273138 is an apocalyptic number.

21533273138 is a deficient number, since it is larger than the sum of its proper divisors (13251245050).

21533273138 is a wasteful number, since it uses less digits than its factorization.

21533273138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 828202828.

The product of its digits is 90720, while the sum is 38.

The spelling of 21533273138 in words is "twenty-one billion, five hundred thirty-three million, two hundred seventy-three thousand, one hundred thirty-eight".