207993639891 has 24 divisors (see below), whose sum is σ = 288154170304. Its totient is φ = 133444372320.

The previous prime is 207993639883. The next prime is 207993639937. The reversal of 207993639891 is 198936399702.

It is a happy number.

207993639891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 207993639891 - 2³ = 207993639883 is a prime.

It is a super-2 number, since 2×207993639891² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (207993639691) 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 23 ways as a sum of consecutive naturals, for example, 640296 + ... + 908826.

Almost surely, 2^207993639891 is an apocalyptic number.

207993639891 is a deficient number, since it is larger than the sum of its proper divisors (80160530413).

207993639891 is a wasteful number, since it uses less digits than its factorization.

207993639891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 268899 (or 268870 counting only the distinct ones).

The product of its (nonzero) digits is 39680928, while the sum is 66.

The spelling of 207993639891 in words is "two hundred seven billion, nine hundred ninety-three million, six hundred thirty-nine thousand, eight hundred ninety-one".