81847430 has 16 divisors (see below), whose sum is σ = 168372000. Its totient is φ = 28061952.

The previous prime is 81847429. The next prime is 81847433. The reversal of 81847430 is 3474818.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81847433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 584555 + ... + 584694.

It is an arithmetic number, because the mean of its divisors is an integer number (10523250).

Almost surely, 2^81847430 is an apocalyptic number.

81847430 is an abundant number, since it is smaller than the sum of its proper divisors (86524570).

81847430 is a wasteful number, since it uses less digits than its factorization.

81847430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1169263.

The product of its (nonzero) digits is 21504, while the sum is 35.

The square root of 81847430 is about 9046.9569469518. The cubic root of 81847430 is about 434.1785351379.

The spelling of 81847430 in words is "eighty-one million, eight hundred forty-seven thousand, four hundred thirty".