81828657 has 8 divisors (see below), whose sum is σ = 121227680. Its totient is φ = 54552420.

The previous prime is 81828653. The next prime is 81828673. The reversal of 81828657 is 75682818.

It is not a de Polignac number, because 81828657 - 2² = 81828653 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81828653) 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, 1515319 + ... + 1515372.

It is an arithmetic number, because the mean of its divisors is an integer number (15153460).

Almost surely, 2^81828657 is an apocalyptic number.

It is an amenable number.

81828657 is a deficient number, since it is larger than the sum of its proper divisors (39399023).

81828657 is a wasteful number, since it uses less digits than its factorization.

81828657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3030700 (or 3030694 counting only the distinct ones).

The product of its digits is 215040, while the sum is 45.

The square root of 81828657 is about 9045.9193562622. The cubic root of 81828657 is about 434.1453373662.

The spelling of 81828657 in words is "eighty-one million, eight hundred twenty-eight thousand, six hundred fifty-seven".