39685022521 has 3 divisors (see below), whose sum is σ = 39685221733. Its totient is φ = 39684823310.

The previous prime is 39685022497. The next prime is 39685022551. The reversal of 39685022521 is 12522058693.

The square root of 39685022521 is 199211.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 39685022521 - 2⁹ = 39685022009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39685022551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 99606 + ... + 298816.

Almost surely, 2^39685022521 is an apocalyptic number.

39685022521 is the 199211-st square number.

39685022521 is the 99606-th centered octagonal number.

It is an amenable number.

39685022521 is a deficient number, since it is larger than the sum of its proper divisors (199212).

39685022521 is an frugal number, since it uses more digits than its factorization.

39685022521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 398422 (or 199211 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 43.

The spelling of 39685022521 in words is "thirty-nine billion, six hundred eighty-five million, twenty-two thousand, five hundred twenty-one".