81838851 has 8 divisors (see below), whose sum is σ = 109772544. Its totient is φ = 54232200.

The previous prime is 81838849. The next prime is 81838879. The reversal of 81838851 is 15883818.

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

It is not a de Polignac number, because 81838851 - 2¹ = 81838849 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81838651) 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, 81175 + ... + 82176.

It is an arithmetic number, because the mean of its divisors is an integer number (13721568).

Almost surely, 2^81838851 is an apocalyptic number.

81838851 is a deficient number, since it is larger than the sum of its proper divisors (27933693).

81838851 is a wasteful number, since it uses less digits than its factorization.

81838851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163521.

The product of its digits is 61440, while the sum is 42.

The square root of 81838851 is about 9046.4827971980. The cubic root of 81838851 is about 434.1633648477.

The spelling of 81838851 in words is "eighty-one million, eight hundred thirty-eight thousand, eight hundred fifty-one".