81402127 has 4 divisors (see below), whose sum is σ = 81948600. Its totient is φ = 80855656.

The previous prime is 81402089. The next prime is 81402131. The reversal of 81402127 is 72120418.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 72120418 = 2 ⋅36060209.

It is a cyclic number.

It is not a de Polignac number, because 81402127 - 2¹⁵ = 81369359 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81402527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 273013 + ... + 273310.

It is an arithmetic number, because the mean of its divisors is an integer number (20487150).

Almost surely, 2^81402127 is an apocalyptic number.

81402127 is a deficient number, since it is larger than the sum of its proper divisors (546473).

81402127 is a wasteful number, since it uses less digits than its factorization.

81402127 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 546472.

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 81402127 is about 9022.3127301153. The cubic root of 81402127 is about 433.3896987167.

The spelling of 81402127 in words is "eighty-one million, four hundred two thousand, one hundred twenty-seven".