8129981 has 4 divisors (see below), whose sum is σ = 8251392. Its totient is φ = 8008572.

The previous prime is 8129963. The next prime is 8129999. The reversal of 8129981 is 1899218.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1899218 = 2 ⋅949609.

It is an interprime number because it is at equal distance from previous prime (8129963) and next prime (8129999).

It is a cyclic number.

It is not a de Polignac number, because 8129981 - 2⁶ = 8129917 is a prime.

It is a super-2 number, since 2×8129981² = 132193182120722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8129921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 60605 + ... + 60738.

It is an arithmetic number, because the mean of its divisors is an integer number (2062848).

Almost surely, 2^8129981 is an apocalyptic number.

It is an amenable number.

8129981 is a deficient number, since it is larger than the sum of its proper divisors (121411).

8129981 is a wasteful number, since it uses less digits than its factorization.

8129981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121410.

The product of its digits is 10368, while the sum is 38.

The square root of 8129981 is about 2851.3121540792. The cubic root of 8129981 is about 201.0773610451.

The spelling of 8129981 in words is "eight million, one hundred twenty-nine thousand, nine hundred eighty-one".