7938791906981 has 32 divisors (see below), whose sum is σ = 9107732067840. Its totient is φ = 6859273688064.

The previous prime is 7938791906957. The next prime is 7938791906989. The reversal of 7938791906981 is 1896091978397.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7938791906981 is a prime.

It is a super-2 number, since 2×7938791906981² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7938791906989) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8399156 + ... + 9296418.

It is an arithmetic number, because the mean of its divisors is an integer number (284616627120).

Almost surely, 2^{7938791906981} is an apocalyptic number.

It is an amenable number.

7938791906981 is a deficient number, since it is larger than the sum of its proper divisors (1168940160859).

7938791906981 is a wasteful number, since it uses less digits than its factorization.

7938791906981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 897725.

The product of its (nonzero) digits is 370355328, while the sum is 77.

The spelling of 7938791906981 in words is "seven trillion, nine hundred thirty-eight billion, seven hundred ninety-one million, nine hundred six thousand, nine hundred eighty-one".