81687826395 has 48 divisors (see below), whose sum is σ = 164472514752. Its totient is φ = 36730817280.

The previous prime is 81687826393. The next prime is 81687826427. The reversal of 81687826395 is 59362878618.

81687826395 is a `hidden beast` number, since 8 + 168 + 7 + 82 + 6 + 395 = 666.

It is not a de Polignac number, because 81687826395 - 2¹ = 81687826393 is a prime.

It is a super-2 number, since 2×81687826395² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (81687826391) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2106412 + ... + 2144841.

It is an arithmetic number, because the mean of its divisors is an integer number (3426510724).

Almost surely, 2^81687826395 is an apocalyptic number.

81687826395 is an abundant number, since it is smaller than the sum of its proper divisors (82784688357).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81687826395 is a wasteful number, since it uses less digits than its factorization.

81687826395 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4251332 (or 4251329 counting only the distinct ones).

The product of its digits is 34836480, while the sum is 63.

The spelling of 81687826395 in words is "eighty-one billion, six hundred eighty-seven million, eight hundred twenty-six thousand, three hundred ninety-five".