81838706 has 16 divisors (see below), whose sum is σ = 127060920. Its totient is φ = 39505920.

The previous prime is 81838699. The next prime is 81838727. The reversal of 81838706 is 60783818.

It can be written as a sum of positive squares in 4 ways, for example, as 64657681 + 17181025 = 8041^2 + 4145^2 .

It is a Harshad number since it is a multiple of its sum of digits (41).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2810 + ... + 13098.

Almost surely, 2^81838706 is an apocalyptic number.

81838706 is a deficient number, since it is larger than the sum of its proper divisors (45222214).

81838706 is a wasteful number, since it uses less digits than its factorization.

81838706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10429.

The product of its (nonzero) digits is 64512, while the sum is 41.

The square root of 81838706 is about 9046.4747830301. The cubic root of 81838706 is about 434.1631084344.

The spelling of 81838706 in words is "eighty-one million, eight hundred thirty-eight thousand, seven hundred six".