7989981 has 8 divisors (see below), whose sum is σ = 10788480. Its totient is φ = 5259072.

The previous prime is 7989973. The next prime is 7990001. The reversal of 7989981 is 1899897.

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

It is not a de Polignac number, because 7989981 - 2³ = 7989973 is a prime.

It is a super-2 number, since 2×7989981² = 127679592760722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7982981) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16620 + ... + 17093.

It is an arithmetic number, because the mean of its divisors is an integer number (1348560).

Almost surely, 2^7989981 is an apocalyptic number.

It is an amenable number.

7989981 is a deficient number, since it is larger than the sum of its proper divisors (2798499).

7989981 is a wasteful number, since it uses less digits than its factorization.

7989981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33795.

The product of its digits is 326592, while the sum is 51.

The square root of 7989981 is about 2826.6554441601. The cubic root of 7989981 is about 199.9164734548.

The spelling of 7989981 in words is "seven million, nine hundred eighty-nine thousand, nine hundred eighty-one".