81375886 has 8 divisors (see below), whose sum is σ = 127371024. Its totient is φ = 38918880.

The previous prime is 81375883. The next prime is 81375887. The reversal of 81375886 is 68857318.

81375886 = T₇₃₆₄ + T₇₃₆₅ + T₇₃₆₆.

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

It is a Harshad number since it is a multiple of its sum of digits (46), and also a Moran number because the ratio is a prime number: 1769041 = 81375886 / (8 + 1 + 3 + 7 + 5 + 8 + 8 + 6).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81375883) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 884475 + ... + 884566.

It is an arithmetic number, because the mean of its divisors is an integer number (15921378).

Almost surely, 2^81375886 is an apocalyptic number.

81375886 is the 7366-th centered triangular number.

81375886 is a deficient number, since it is larger than the sum of its proper divisors (45995138).

81375886 is a wasteful number, since it uses less digits than its factorization.

81375886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1769066.

The product of its digits is 322560, while the sum is 46.

The square root of 81375886 is about 9020.8583848767. The cubic root of 81375886 is about 433.3431241706.

The spelling of 81375886 in words is "eighty-one million, three hundred seventy-five thousand, eight hundred eighty-six".