39820197887 has 4 divisors (see below), whose sum is σ = 40008919416. Its totient is φ = 39631476360.

The previous prime is 39820197871. The next prime is 39820197983. The reversal of 39820197887 is 78879102893.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78879102893 = 17 ⋅4639947229.

It is a cyclic number.

It is not a de Polignac number, because 39820197887 - 2⁴ = 39820197871 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39820127887) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 94360448 + ... + 94360869.

It is an arithmetic number, because the mean of its divisors is an integer number (10002229854).

Almost surely, 2^39820197887 is an apocalyptic number.

39820197887 is a deficient number, since it is larger than the sum of its proper divisors (188721529).

39820197887 is a wasteful number, since it uses less digits than its factorization.

39820197887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188721528.

The product of its (nonzero) digits is 12192768, while the sum is 62.

The spelling of 39820197887 in words is "thirty-nine billion, eight hundred twenty million, one hundred ninety-seven thousand, eight hundred eighty-seven".