8391651838 has 4 divisors (see below), whose sum is σ = 12587477760. Its totient is φ = 4195825918.

The previous prime is 8391651811. The next prime is 8391651887. The reversal of 8391651838 is 8381561938.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8381561938 = 2 ⋅4190780969.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2097912958 + ... + 2097912961.

It is an arithmetic number, because the mean of its divisors is an integer number (3146869440).

Almost surely, 2^8391651838 is an apocalyptic number.

8391651838 is a deficient number, since it is larger than the sum of its proper divisors (4195825922).

8391651838 is a wasteful number, since it uses less digits than its factorization.

8391651838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4195825921.

The product of its digits is 1244160, while the sum is 52.

The square root of 8391651838 is about 91605.9596205400. The cubic root of 8391651838 is about 2032.1190744322.

The spelling of 8391651838 in words is "eight billion, three hundred ninety-one million, six hundred fifty-one thousand, eight hundred thirty-eight".