81849215 has 8 divisors (see below), whose sum is σ = 112250400. Its totient is φ = 56125152.

The previous prime is 81849211. The next prime is 81849227. The reversal of 81849215 is 51294818.

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

It is a cyclic number.

It is not a de Polignac number, because 81849215 - 2² = 81849211 is a prime.

It is a super-2 number, since 2×81849215² = 13398587992232450, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81849211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1169240 + ... + 1169309.

It is an arithmetic number, because the mean of its divisors is an integer number (14031300).

Almost surely, 2^81849215 is an apocalyptic number.

81849215 is a deficient number, since it is larger than the sum of its proper divisors (30401185).

81849215 is a wasteful number, since it uses less digits than its factorization.

81849215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2338561.

The product of its digits is 23040, while the sum is 38.

The square root of 81849215 is about 9047.0555983701. The cubic root of 81849215 is about 434.1816914295.

The spelling of 81849215 in words is "eighty-one million, eight hundred forty-nine thousand, two hundred fifteen".