81099408 has 40 divisors (see below), whose sum is σ = 225624448. Its totient is φ = 24953472.

The previous prime is 81099407. The next prime is 81099409. The reversal of 81099408 is 80499018.

It is an interprime number because it is at equal distance from previous prime (81099407) and next prime (81099409).

It is a super-2 number, since 2×81099408² = 13154227955900928, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (81099407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64360 + ... + 65607.

Almost surely, 2^81099408 is an apocalyptic number.

It is an amenable number.

81099408 is an abundant number, since it is smaller than the sum of its proper divisors (144525040).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81099408 is a wasteful number, since it uses less digits than its factorization.

81099408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129991 (or 129985 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 39.

The square root of 81099408 is about 9005.5209732697. The cubic root of 81099408 is about 432.8518001466.

The spelling of 81099408 in words is "eighty-one million, ninety-nine thousand, four hundred eight".