7918809381 has 12 divisors (see below), whose sum is σ = 13072320352. Its totient is φ = 4525033896.

The previous prime is 7918809377. The next prime is 7918809383. The reversal of 7918809381 is 1839088197.

It is not a de Polignac number, because 7918809381 - 2² = 7918809377 is a prime.

It is a super-2 number, since 2×7918809381² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7918809383) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 62847631 + ... + 62847756.

Almost surely, 2^7918809381 is an apocalyptic number.

It is an amenable number.

7918809381 is a deficient number, since it is larger than the sum of its proper divisors (5153510971).

7918809381 is a wasteful number, since it uses less digits than its factorization.

7918809381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125695400 (or 125695397 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 54.

The square root of 7918809381 is about 88987.6923006772. The cubic root of 7918809381 is about 1993.2110965529.

The spelling of 7918809381 in words is "seven billion, nine hundred eighteen million, eight hundred nine thousand, three hundred eighty-one".