21852506738 has 4 divisors (see below), whose sum is σ = 32778760110. Its totient is φ = 10926253368.

The previous prime is 21852506719. The next prime is 21852506743. The reversal of 21852506738 is 83760525812.

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., 16660871929 + 5191634809 = 129077^2 + 72053^2 .

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21852506692 and 21852506701.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5463126683 + ... + 5463126686.

Almost surely, 2^21852506738 is an apocalyptic number.

21852506738 is a deficient number, since it is larger than the sum of its proper divisors (10926253372).

21852506738 is a wasteful number, since it uses less digits than its factorization.

21852506738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10926253371.

The product of its (nonzero) digits is 806400, while the sum is 47.

The spelling of 21852506738 in words is "twenty-one billion, eight hundred fifty-two million, five hundred six thousand, seven hundred thirty-eight".