7981918838 has 8 divisors (see below), whose sum is σ = 11973442032. Its totient is φ = 3990771496.

The previous prime is 7981918783. The next prime is 7981918883. The reversal of 7981918838 is 8388191897.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×7981918838² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 32945 + ... + 130572.

It is an arithmetic number, because the mean of its divisors is an integer number (1496680254).

Almost surely, 2^7981918838 is an apocalyptic number.

7981918838 is a deficient number, since it is larger than the sum of its proper divisors (3991523194).

7981918838 is a wasteful number, since it uses less digits than its factorization.

7981918838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187926.

The product of its digits is 6967296, while the sum is 62.

The square root of 7981918838 is about 89341.5851549546. The cubic root of 7981918838 is about 1998.4920999044.

The spelling of 7981918838 in words is "seven billion, nine hundred eighty-one million, nine hundred eighteen thousand, eight hundred thirty-eight".