21073050538 has 4 divisors (see below), whose sum is σ = 31609575810. Its totient is φ = 10536525268.

The previous prime is 21073050521. The next prime is 21073050539. The reversal of 21073050538 is 83505037012.

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

It can be written as a sum of positive squares in only one way, i.e., 15583277889 + 5489772649 = 124833^2 + 74093^2 .

It is not an unprimeable number, because it can be changed into a prime (21073050539) 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 as a sum of consecutive naturals, namely, 5268262633 + ... + 5268262636.

Almost surely, 2^21073050538 is an apocalyptic number.

21073050538 is a deficient number, since it is larger than the sum of its proper divisors (10536525272).

21073050538 is a wasteful number, since it uses less digits than its factorization.

21073050538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10536525271.

The product of its (nonzero) digits is 25200, while the sum is 34.

The spelling of 21073050538 in words is "twenty-one billion, seventy-three million, fifty thousand, five hundred thirty-eight".