81828687 has 16 divisors (see below), whose sum is σ = 119842560. Its totient is φ = 49433472.

The previous prime is 81828673. The next prime is 81828697. The reversal of 81828687 is 78682818.

It is not a de Polignac number, because 81828687 - 2¹⁰ = 81827663 is a prime.

It is a super-2 number, since 2×81828687² = 13391868032287938, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81828697) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29898 + ... + 32519.

It is an arithmetic number, because the mean of its divisors is an integer number (7490160).

Almost surely, 2^81828687 is an apocalyptic number.

81828687 is a deficient number, since it is larger than the sum of its proper divisors (38013873).

81828687 is a wasteful number, since it uses less digits than its factorization.

81828687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62462.

The product of its digits is 344064, while the sum is 48.

The square root of 81828687 is about 9045.9210144683. The cubic root of 81828687 is about 434.1453904216.

The spelling of 81828687 in words is "eighty-one million, eight hundred twenty-eight thousand, six hundred eighty-seven".