81849099 has 4 divisors (see below), whose sum is σ = 109132136. Its totient is φ = 54566064.

The previous prime is 81849091. The next prime is 81849149. The reversal of 81849099 is 99094818.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 81849099 - 2³ = 81849091 is a prime.

It is a super-2 number, since 2×81849099² = 13398550014223602, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81849091) 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 3 ways as a sum of consecutive naturals, for example, 13641514 + ... + 13641519.

It is an arithmetic number, because the mean of its divisors is an integer number (27283034).

Almost surely, 2^81849099 is an apocalyptic number.

81849099 is a deficient number, since it is larger than the sum of its proper divisors (27283037).

81849099 is a wasteful number, since it uses less digits than its factorization.

81849099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27283036.

The product of its (nonzero) digits is 186624, while the sum is 48.

The square root of 81849099 is about 9047.0491874423. The cubic root of 81849099 is about 434.1814863161.

The spelling of 81849099 in words is "eighty-one million, eight hundred forty-nine thousand, ninety-nine".