81427470 has 16 divisors (see below), whose sum is σ = 195426000. Its totient is φ = 21713984.

The previous prime is 81427427. The next prime is 81427499. The reversal of 81427470 is 7472418.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1357095 + ... + 1357154.

It is an arithmetic number, because the mean of its divisors is an integer number (12214125).

Almost surely, 2^81427470 is an apocalyptic number.

81427470 is an abundant number, since it is smaller than the sum of its proper divisors (113998530).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81427470 is a wasteful number, since it uses less digits than its factorization.

81427470 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2714259.

The product of its (nonzero) digits is 12544, while the sum is 33.

The square root of 81427470 is about 9023.7170833310. The cubic root of 81427470 is about 433.4346699228.

Adding to 81427470 its reverse (7472418), we get a palindrome (88899888).

The spelling of 81427470 in words is "eighty-one million, four hundred twenty-seven thousand, four hundred seventy".