81809098 has 24 divisors (see below), whose sum is σ = 148023072. Its totient is φ = 33213672.

The previous prime is 81809069. The next prime is 81809149. The reversal of 81809098 is 89090818.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3040 + ... + 13147.

It is an arithmetic number, because the mean of its divisors is an integer number (6167628).

Almost surely, 2^81809098 is an apocalyptic number.

81809098 is a deficient number, since it is larger than the sum of its proper divisors (66213974).

81809098 is a wasteful number, since it uses less digits than its factorization.

81809098 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16234 (or 16215 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 43.

The square root of 81809098 is about 9044.8381964522. The cubic root of 81809098 is about 434.1107442477.

The spelling of 81809098 in words is "eighty-one million, eight hundred nine thousand, ninety-eight".