81886207 has 4 divisors (see below), whose sum is σ = 88185160. Its totient is φ = 75587256.

The previous prime is 81886201. The next prime is 81886213. The reversal of 81886207 is 70268818.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (81886201) and next prime (81886213).

It is a cyclic number.

It is not a de Polignac number, because 81886207 - 2³ = 81886199 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81886207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81886201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3149457 + ... + 3149482.

It is an arithmetic number, because the mean of its divisors is an integer number (22046290).

Almost surely, 2^81886207 is an apocalyptic number.

81886207 is a deficient number, since it is larger than the sum of its proper divisors (6298953).

81886207 is a wasteful number, since it uses less digits than its factorization.

81886207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6298952.

The product of its (nonzero) digits is 43008, while the sum is 40.

The square root of 81886207 is about 9049.0997894818. The cubic root of 81886207 is about 434.2470914869.

It can be divided in two parts, 818 and 86207, that added together give a square (87025 = 295²).

The spelling of 81886207 in words is "eighty-one million, eight hundred eighty-six thousand, two hundred seven".