81551827 has 12 divisors (see below), whose sum is σ = 95217816. Its totient is φ = 69642720.

The previous prime is 81551801. The next prime is 81551831. The reversal of 81551827 is 72815518.

It is not a de Polignac number, because 81551827 - 2¹⁹ = 81027539 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81551867) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10927 + ... + 16807.

It is an arithmetic number, because the mean of its divisors is an integer number (7934818).

Almost surely, 2^81551827 is an apocalyptic number.

81551827 is a deficient number, since it is larger than the sum of its proper divisors (13665989).

81551827 is a wasteful number, since it uses less digits than its factorization.

81551827 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6178 (or 6171 counting only the distinct ones).

The product of its digits is 22400, while the sum is 37.

The square root of 81551827 is about 9030.6050184913. The cubic root of 81551827 is about 433.6552065520.

The spelling of 81551827 in words is "eighty-one million, five hundred fifty-one thousand, eight hundred twenty-seven".