108218991 has 8 divisors (see below), whose sum is σ = 152779824. Its totient is φ = 67902080.

The previous prime is 108218989. The next prime is 108218993. The reversal of 108218991 is 199812801.

It is an interprime number because it is at equal distance from previous prime (108218989) and next prime (108218993).

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

It is not a de Polignac number, because 108218991 - 2¹ = 108218989 is a prime.

It is a super-2 number, since 2×108218991² = 23422700026116162, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (108218993) 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, 1060920 + ... + 1061021.

It is an arithmetic number, because the mean of its divisors is an integer number (19097478).

Almost surely, 2^108218991 is an apocalyptic number.

108218991 is a deficient number, since it is larger than the sum of its proper divisors (44560833).

108218991 is a wasteful number, since it uses less digits than its factorization.

108218991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2121961.

The product of its (nonzero) digits is 10368, while the sum is 39.

The square root of 108218991 is about 10402.8357191681. The cubic root of 108218991 is about 476.5419747089.

The spelling of 108218991 in words is "one hundred eight million, two hundred eighteen thousand, nine hundred ninety-one".