81431430 has 32 divisors (see below), whose sum is σ = 196871904. Its totient is φ = 21555456.

The previous prime is 81431429. The next prime is 81431447. The reversal of 81431430 is 3413418.

It is a self number, because there is not a number n which added to its sum of digits gives 81431430.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 5797 + ... + 14016.

It is an arithmetic number, because the mean of its divisors is an integer number (6152247).

Almost surely, 2^81431430 is an apocalyptic number.

81431430 is an abundant number, since it is smaller than the sum of its proper divisors (115440474).

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

81431430 is a wasteful number, since it uses less digits than its factorization.

81431430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19960.

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 81431430 is about 9023.9365024362. The cubic root of 81431430 is about 433.4416961081.

Adding to 81431430 its reverse (3413418), we get a palindrome (84844848).

The spelling of 81431430 in words is "eighty-one million, four hundred thirty-one thousand, four hundred thirty".