39438973821 has 24 divisors (see below), whose sum is σ = 56958735360. Its totient is φ = 24262782336.

The previous prime is 39438973801. The next prime is 39438973879. The reversal of 39438973821 is 12837983493.

It is not a de Polignac number, because 39438973821 - 2⁶ = 39438973757 is a prime.

It is a hoax number, since the sum of its digits (57) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39438973801) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2001465 + ... + 2021073.

It is an arithmetic number, because the mean of its divisors is an integer number (2373280640).

Almost surely, 2^39438973821 is an apocalyptic number.

It is an amenable number.

39438973821 is a deficient number, since it is larger than the sum of its proper divisors (17519761539).

39438973821 is a wasteful number, since it uses less digits than its factorization.

39438973821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23605 (or 23592 counting only the distinct ones).

The product of its digits is 7838208, while the sum is 57.

The spelling of 39438973821 in words is "thirty-nine billion, four hundred thirty-eight million, nine hundred seventy-three thousand, eight hundred twenty-one".