81886651 has 8 divisors (see below), whose sum is σ = 102092544. Its totient is φ = 63807720.

The previous prime is 81886639. The next prime is 81886667. The reversal of 81886651 is 15668818.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 81886651 - 2¹⁵ = 81853883 is a prime.

It is a super-2 number, since 2×81886651² = 13410847223991602, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81886598 and 81886607.

It is not an unprimeable number, because it can be changed into a prime (81886621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 531655 + ... + 531808.

It is an arithmetic number, because the mean of its divisors is an integer number (12761568).

Almost surely, 2^81886651 is an apocalyptic number.

81886651 is a deficient number, since it is larger than the sum of its proper divisors (20205893).

81886651 is a wasteful number, since it uses less digits than its factorization.

81886651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1063481.

The product of its digits is 92160, while the sum is 43.

The square root of 81886651 is about 9049.1243222756. The cubic root of 81886651 is about 434.2478763377.

The spelling of 81886651 in words is "eighty-one million, eight hundred eighty-six thousand, six hundred fifty-one".